Rapid screening method for non-orthophthalic plasticizer in processed food

Abstract

The invention provides a rapid screening method for non-phthalate plasticizers in processed food. According to the rapid screening method, 36 non-phthalate plasticizers are detected by adopting gas chromatography-quadrupole rod / electrostatic field orbitrap high-resolution mass spectrometry. According to the method, efficient purification of the non-phthalate plasticizer in various typical processed foods such as wine, edible vegetable oil and infant formula milk powder can be realized by adopting a QuERChERS method, the pretreatment process is greatly simplified, and the detection efficiency is improved; a high-resolution mass spectrum full-scanning determination strategy is adopted in a breakthrough manner, so that the detection precision is improved, a reliable data basis is provided for subsequent traceability analysis, and the technical route is obviously different from a low-resolution mass spectrometry method which is generally adopted in the prior art; according to the method, high-throughput and high-sensitivity screening and confirmation under the condition of no standard substance are innovatively realized, the detection cost is remarkably reduced, and the practical value of the method is improved. Based on the screening confirmation strategy provided by the invention, the urgent requirements of food quality safety supervision and novel pollutant risk monitoring can be effectively met, and the method has good popularization and application prospects.

Description

Technical Field

[0001] The present invention relates to a rapid screening method for non-phthalate plasticizers in processed foods. Background Art

[0002] Plasticizers, also known as plasticizing agents, are widely used as additives such as plasticizers and softeners in the production of polymer plastic products, and mainly exist in food packaging, cosmetics, medical devices, such as food wrap, food packaging, toys, etc. According to different chemical properties, plasticizers are divided into two categories: one is phthalate plasticizers, and the other is non-phthalate plasticizers. Phthalate plasticizers mainly include more than 20 compounds such as DMP, DBP, DIBP, DEHP, etc. There are many types of non-phthalate plasticizers, including aliphatic dibasic acid esters, fatty acid esters, benzene polycarboxylic acid esters, polyol esters, epoxy hydrocarbons, alkyl sulfonates, etc. In the plastic production process, since phthalate plasticizers are not polymerized onto the polyolefin plastic polymer carbon chain, but are combined with the polymer by relatively weak hydrogen bonds or van der Waals forces, when the plastic material comes into contact with food, the plasticizer therein will dissolve and migrate into the food. In recent years, due to the fact that phthalate plasticizers can affect and interfere with the endocrine function of the human body and have reproductive and developmental toxicity, their safety has received attention in the industry. Since food safety incidents such as the Taiwanese beverage clouding agent in 2011 and the plasticizer in a certain white liquor in 2012 occurred, phthalate plasticizers in food contact materials have become the focus of food safety concern as exogenous food contaminants. Countries such as the EU REACH regulation, the United States, Brazil, China, etc. have strictly restricted the use of phthalate plasticizers, and some non-phthalate plasticizers with relatively low toxicity and better stability have gradually developed as substitutes.

[0003] According to their different physical and chemical properties, non-phthalate plasticizers have been widely used in the production process of different products. Among non-phthalate plasticizers, DEHA, DOTP, DINCH, ATBC, ESBO, etc. are mainly used in food packaging and production processes. Currently, the EU Regulation No. 2011 / 10 / EC, China's GB 9685-2016, Switzerland, Brazil, etc. have clear limit regulations on bis(2-ethylhexyl) adipate (DEHA), bis(2-ethylhexyl) terephthalate (DOTP), bis(2-ethylhexyl) sebacate DEHS and dibutyl sebacate (DBS). There are no relevant limit values for the remaining non-phthalate plasticizers. Since in the food packaging and production process, plasticizers are very likely to migrate into food and water, continuous exposure will still pose a hazard to human health. Therefore, it is necessary to conduct relevant research on non-phthalate plasticizers in food.

[0004] Like phthalate plasticizers, non-phthalate plasticizers are mostly lipophilic compounds. When plastic products come into contact with alcoholic beverages and vegetable oils, the migration risk increases, which to a certain extent poses potential food safety hazards. During the production process of Chinese liquor, plastic products (such as plastic films, plastic storage containers, plastic pipes, etc.), coatings on packaging, rubber products, adhesives and sealants, as well as additives such as flavors and fragrances that may be used in the production of new process Chinese liquor, may all introduce plasticizer pollution. During the production process of vegetable oil, plasticizer pollution mainly comes from raw material pollution, introduction during the processing process, packaging materials, and illegal addition. During the production process of milk powder, the use of PVC hoses for milk source collection, dust in the environment, plastic pipes during the production process, containers and packaging for storing milk and milk powder all pose the risk of plasticizer migration into milk powder. Based on the risks of non-phthalate plasticizers migrating into these three types of foods, namely alcoholic beverages, edible vegetable oils, infant formula milk powder, and food, it is therefore necessary to establish a universal, efficient, and high-throughput detection technology for non-phthalate plasticizers in typical processed foods (alcoholic beverages, edible vegetable oils, infant formula milk powder, and food), implement daily risk monitoring, provide technical means for relevant departments to conduct risk assessment, and at the same time contribute to the improvement of relevant standards or the supplementation of inspection methods.

[0005] At present, the main methods for determining plasticizers include: gas chromatography-mass spectrometry (GC-MS), liquid chromatography-mass spectrometry (HPLC-MS), electrochemical detection method, and surface-enhanced Raman spectroscopy (SERS). The relevant standards mainly include GB5009.271-2016 "National Food Safety Standard - Determination of Phthalate Esters in Foods" (GC-MS method), SN / T 3147-2017 "Determination Method of Phthalate Esters in Export Foods" (HPLC-MS method), and GB 31604.30-2016 "National Food Safety Standard - Determination and Migration Amount Determination of Phthalate Esters in Food Contact Materials and Articles" (GC-MS method). The relevant literature mainly includes: Arena et al. [ARENAA., ZOCCALI M., MONDELLO L., et al. Direct analysis of phthalate esters in vegetable oils by means of comprehensive two-dimensional gas chromatography combined with triple quadrupole mass spectrometry [J]. Food Chem, 2022, 396: 133721.] established a method for directly analyzing PAEs in vegetable oils without sample pretreatment by comprehensive two-dimensional gas chromatography combined with triple quadrupole mass spectrometry (GC×GC-QQQMS). Li et al. [LI X., ZHANG Q., CHEN L., et al. Determination of 16 phthalate esters in sesame oil by isotope dilution liquid chromatography with tandem mass spectrometry [J]. Anal. Methods, 2018, (26): 3197-3206.] quantitatively measured 16 PAEs in sesame oil by LC-MS / MS after extraction with acetonitrile-saturated n-hexane and purification through a PSA solid-phase extraction column. Ge Zipan et al. [Ge Zipan, Zhang Le, Wang Xinru, et al. Preparation of surface-enhanced Raman scattering spectroscopy substrates of gold-coated silver nanocubes and their detection of plasticizers [J]. New Chemical Materials, 2020, (6): 236-241, 246.] compared two substrate materials, gold-coated silver nanorod nanocubes (AuNR@Ag NCs) and gold-coated silver particle nanocubes (AuNS@Ag NCs). Using crystal violet (CV) as a Raman probe, AuNR@Ag NCs is better, and the detection limit for BBP can reach 10 -9mol / L and has high detection sensitivity. Xiong et al. [Xiong S.Q., Cheng J., He L., et al. Fabrication of β-cyclodextrin / graphene / 1,10-diaminodecane composite on glassy carbon electrode and impedimetric method for Di(2-ethyl hexyl)phthalate determination [J]. J Electro anal Chem, 2015, (743): 18-24.] used a β-cyclodextrin-graphene (βCD-G) hybrid composite modified glassy carbon electrode for the electrochemical detection of DEHP. On the composite electrode, the impedance value showed a good linear relationship with the DEHP concentration in the range of 2-18 μM, and the detection limit was 0.12 μM. In summary, with the cross-integration of multi-disciplines such as instrumental analysis, molecular biology, and materials science, the detection sensitivity and accuracy of phthalate plasticizers are continuously improving.

[0006] At present, the detection methods for non-phthalate plasticizers mainly include: GC-MS / MS, GC-Q / TOF. The relevant standards are only: BJS202101 "Determination of Dioctyl Terephthalate in Foods" (GC-MS method), and there are relatively many relevant literature reports. There are mainly the detection of non-phthalate plasticizers in white liquor, infant formula, and milk beverages by GC-MS / MS, and the detection of non-phthalate plasticizers in sesame oil by GC-Q / TOF. Gimen et al. used the GC-MS method to determine 14 phthalates and 5 non-phthalate plasticizers in PVC medical devices. Compared with the diversity of methods for determining phthalate plasticizers, the relevant methods for non-phthalate plasticizers are relatively few.

[0007] High-resolution mass spectrometry (HRMS) can accurately identify and quantify compounds in complex matrices due to its high resolution, high sensitivity, and high mass accuracy. Currently, widely used high-resolution mass spectrometers include quadrupole time-of-flight mass spectrometry (Q-TOF MS), electrostatic field orbitrap high-resolution mass spectrometry (Orbitrap HRMS), double-focusing sector magnetic mass spectrometry (Magnetic HRMS), and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). In recent years, non-target analysis methods using HRMS have mainly been used for screening mycotoxins, pesticide residues, pigments, etc. in food. The gas chromatography-high-resolution mass spectrometry (GC-Q / Orbitrap HRMS) has the characteristics of high resolution, high mass accuracy, and good sensitivity. In the full-scan mode, it can collect the full spectrum of the accurate mass numbers of target compounds at low content levels in complex matrices, enabling efficient screening and quantification. By establishing a database, it is possible to rapidly identify target substances without using standard substances and perform retrospective analysis on new target substances, increasing the number of target substances screened simultaneously. Detecting non-phthalate plasticizers by GC-Q / Orbitrap HRMS requires overcoming multiple challenges such as matrix interference, deconvolution algorithms, resolution optimization selection, sensitivity, isomer differentiation, sample pretreatment complexity, and high-resolution spectrum analysis. Summary of the Invention

[0008] According to the migration characteristics of non-phthalate esters, the characteristics of food, and packaging materials, the present invention mainly studies the determination of non-phthalate esters in 3 types of typical processed foods (liquors, edible vegetable oils, infant formula milk powders, and foods). The present invention provides a rapid screening method for non-phthalate plasticizers in processed foods.

[0009] The present invention provides a rapid screening method for non-phthalate plasticizers in processed foods, which uses gas chromatography-quadrupole / electrostatic field orbitrap high-resolution mass spectrometry to detect 36 non-phthalate ester plasticizers;

[0010] Among them, the gas chromatography conditions are as follows: chromatographic column: HP-5MS UI chromatographic column (the stationary phase is 5% phenyl + 95% polydimethylsiloxane) (30 m × 0.25 mm × 0.25 μm); inlet temperature: 250 °C; transfer line temperature 1: 260 °C, transfer line temperature 2: 280 °C; injection volume: 1 μL; carrier gas: helium, 1 mL / min; splitless injection; programmed temperature rise: hold at 50 °C for 1 min, raise the temperature to 220 °C at a rate of 20 °C / min, then raise the temperature to 280 °C at a rate of 5 °C / min, and then raise the temperature to 310 °C at a rate of 10 °C / min, and hold for 10 min;

[0011] Mass spectrometry conditions: electron impact ionization source (EI source, 70 eV); ion source temperature: 280 °C, transfer line temperature: 280 °C. Solvent delay: 4 min. Acquisition mode: full scan mode, m / z scan range is 50 - 400, AGC: 1×e 6 , resolution: 60000.

[0012] Among them, the 36 non-phthalate plasticizers are: triethyl phosphate, diethyl maleate, 2-ethylhexyl acrylate, dimethyl adipate, diethyl adipate, diisobutyl fumarate, dimethyl terephthalate, dimethyl isophthalate, dibutyl maleate, dimethyl azelate, dibutyl fumarate, dibutyl itaconate, dimethyl sebacate, tributyl phosphate, diethyl azelate, dibutyl adipate, diethyl sebacate, diethylhexyl maleate, dibutyl sebacate, bis(2-ethylhexyl) itaconate, bis(2-ethylhexyl) fumarate, bis(2-ethylhexyl) adipate, triphenyl phosphate, diphenyl isooctyl phosphate, tris(2-ethylhexyl) phosphate, di-n-octyl adipate, o-cresyl phosphate, m-cresyl phosphate, bis(2-ethylhexyl) isophthalate, bis(2-ethylhexyl) azelate, diphenyl isophthalate, diphenyl terephthalate, bis(2-ethylhexyl) terephthalate, tris(p-tolyl) phosphate, bis(2-ethylhexyl) sebacate, di-n-octyl isophthalate.

[0013] Among them, the processed foods are: alcoholic beverages, edible vegetable oils, infant formula milk powder, and food.

[0014] Specifically, it includes the following steps:

[0015] a. Sample pretreatment;

[0016] b. Detect using the gas chromatography conditions and mass spectrometry conditions described in claim 1.

[0017] 5. The rapid screening method for non-phthalate plasticizers in processed foods according to claim 4, characterized in that: the method of sample pretreatment includes:

[0018] (1) Alcoholic beverages

[0019] Accurately weigh 1.0 g of the sample into a 25-mL stoppered ground-glass tube. Accurately add 10 mL of n-hexane, vortex for 5 min, ultrasonically extract for 30 min, and centrifuge at 1000 r / min for 5 min. Take 2.5 mL of the supernatant into a 10-mL glass tube for nitrogen blowing. Nitrogen-blow to near dryness in a 40 °C water bath, accurately dilute to 1.0 mL with n-hexane, vortex to mix evenly, and use for GC-Q / Orbitrap HRMS analysis.

[0020] (2) Vegetable oil

[0021] Accurately weigh 0.5 g of the sample into a 25-mL stoppered ground-glass tube. Accurately add 10 mL of acetonitrile, vortex for 5 min, ultrasonically extract for 30 min, and centrifuge at 1000 r / min for 5 min. The supernatant is to be purified; Pipette 7 mL of the supernatant into a 10-mL glass tube containing 500 mg of Silica, 500 mg of PSA, and 50 mg of C 18 . Vortex to mix evenly for 5 min and centrifuge at 1000 r / min for 5 min. Accurately pipette 5 mL of the supernatant into a 10-mL glass tube for nitrogen blowing. Nitrogen-blow to near dryness in a 40 °C water bath, accurately dilute to 1.0 mL with n-hexane, vortex to mix evenly, and use for GC-Q / Orbitrap HRMS analysis.

[0022] (3) Milk powder sample

[0023] Accurately weigh 0.5 g of the sample into a 25-mL stoppered ground-glass tube, add 2 mL of 20% NaCl solution, then accurately add 10 mL of acetonitrile, vortex for 5 min, ultrasonically extract for 30 min, add 1 g of NaCl, mix well, and then centrifuge at 1000 r / min for 5 min. The supernatant is to be purified; Pipette 7 mL of the supernatant into a 10-mL glass tube containing 500 mg of Silica, 500 mg of PSA, and 50 mg of C 18 . Vortex to mix evenly for 5 min and centrifuge at 1000 r / min for 5 min. Accurately pipette 5 mL of the supernatant into a 10-mL glass tube for nitrogen blowing. Nitrogen-blow to near dryness in a 40 °C water bath, accurately dilute to 1.0 mL with n-hexane, vortex to mix evenly, and use for GC-Q / Orbitrap HRMS analysis.

[0024] The present invention provides a high-resolution mass spectrometry screening database for non-neighboring phthalate plasticizers in processed foods, which is the high-resolution screening information of 36 non-phthalate plasticizers obtained by using the rapid screening method for non-neighboring phthalate plasticizers in processed foods.

[0025] Among them, the high-resolution screening information of the 36 non-phthalate plasticizers is shown in the following table:

[0026]

[0027]

[0028] The present invention uses a gas chromatography-high resolution mass spectrometry (GC-Q / Orbitrap HRMS) to study the detection method of 36 non-phthalate plasticizers in typical processed foods (liquors, edible vegetable oils, infant formula milk powders, and foods). According to the physical and chemical properties of the 36 non-phthalate plasticizers, by investigating the extractant, extraction time, purification method, etc., a pretreatment method for 36 non-phthalate plasticizers in milk powder with strong generality and good reproducibility was established. And this method was applied to the risk monitoring of non-phthalate plasticizers in more than 100 batches of samples such as milk powder, white liquor, and edible vegetable oil.

[0029] The purpose of this invention patent is to solve the problems existing in the detection methods of typical food non-phthalate plasticizers in the prior art, such as complex operation, high cost, and limited scope of application. Compared with the prior art, the present invention has significant novelty, innovation, and practicality: 1. The present invention innovatively adopts the QuERChERS method to achieve efficient purification of non-phthalate plasticizers in various typical processed foods such as liquors, edible vegetable oils, and infant formula milk powders, greatly simplifying the pretreatment process and improving the detection efficiency; 2. Breakthroughly adopts the high-resolution mass spectrometry full-scan determination strategy, which not only improves the detection accuracy but also provides a reliable data basis for subsequent retrospective analysis. This technical route is significantly different from the low-resolution mass spectrometry method commonly used in the prior art; 3. This method innovatively realizes high-throughput and high-sensitivity screening and confirmation under the condition of no standard substance, significantly reducing the detection cost and improving the practical value of the method; 4. Compared with traditional phthalate plasticizers, there are many types and complex structures of new non-phthalate plasticizers, and there are many isomers. The low-resolution screening method adopted by the traditional method has low resolution and weak anti-interference ability, making it difficult to distinguish such compounds. The high-resolution mass spectrometry adopted by the present invention can effectively distinguish non-phthalate plasticizers with similar structures by accurately identifying the exact mass numbers of compounds. In summary, based on the screening and confirmation strategy proposed by this invention patent, it can effectively meet the urgent needs of food quality and safety supervision and the risk monitoring of new pollutants, and has good prospects for popularization and application. Description of the Drawings

[0030] Figure 1 Total ion chromatogram of 36 non-phthalate plasticizers

[0031] Figure 2 Extracted with methanol in rapeseed oil

[0032] Figure 3 Extracted with acetonitrile in rapeseed oil

[0033] Figure 4 Investigation of Different Concentrations of NaCl in Infant Formula Milk Powder

[0034] Figure 5 Investigation of the Volume of Extraction Solvent in Baijiu

[0035] Figure 6 Investigation of the Volume of Extraction Solvent in Rapeseed Oil

[0036] Figure 7 Investigation of the Volume of Extraction Solvent in Infant Formula Milk Powder

[0037] Figure 8 Investigation of Different Ultrasonic Times in Milk Powder

[0038] Figure 9 Investigation of Different Vortex Times in Infant Formula Milk Powder

[0039] Figure 10 Investigation of Different Silica + PSA Ratios in Rapeseed Oil

[0040] Figure 11 Direct Extraction of Acetonitrile in Rapeseed Oil

[0041] Figure 12 Investigation of the Purification of Acetonitrile Extraction in Rapeseed Oil by QuEChERS

[0042] Figure 13 Investigation of Different Silica + PSA Ratios in Infant Formula Milk Powder

[0043] Figure 14 Investigation of Matrix Effect in Baijiu

[0044] Figure 15 Investigation of Matrix Effect in Rapeseed Oil

[0045] Figure 16 Investigation of Matrix Effect in Infant Formula Milk Powder Specific Embodiments

[0046] Example 1 Rapid Screening Method for Non - Phthalate Plasticizers in Processed Foods of the Present Invention

[0047] 1 Experimental Part

[0048] 1.1 Instruments

[0049] Gas chromatography high-resolution mass spectrometer (GC-Q / Orbitrap HRMS) (Thermo Fisher Scientific, USA); ME203 electronic balance (Mettler Toledo), purified by Milli-Q Direct ultrapure water system with resistivity of 18.2 MΩ / cm (Merck Millipore, Germany); KQ-300DE numerical control ultrasonic cleaner (Kunshan Ultrasonic Instruments Co., Ltd.), RZ-50 centrifuge (Changzhou Yinen Experimental Instrument Factory), vortex mixer (Heidolph, Germany).

[0050] 1.2 Reagents and Consumables

[0051] n-Hexane (mass spectrometry grade, Thermo Fisher Scientific (China) Co., Ltd.), acetonitrile (mass spectrometry grade, Thermo Fisher Scientific (China) Co., Ltd.), sodium chloride (Chongqing Chuandong Chemical (Group) Co., Ltd.), Bondesil bulk adsorbent: 40 μm (Agilent Technologies, USA), ethylenediamine-N-propyl silylated silica gel (PSA): 40 - 60 μm (Agilent Technologies, USA), octadecylsilyl-bonded silica gel (C 18 ): 40 - 60 μm (Agilent Technologies, USA).

[0052] 1.3 Reference Substances

[0053] Reference standards of 36 non-phthalate plasticizers were all purchased from Tianjin Aladdin Chemistry Co., Ltd., and the detailed information is shown in Table 1.

[0054] Table 1 Basic Information Table of 36 Non-phthalate Plasticizers

[0055]

[0056]

[0057]

[0058] 1.4 Preparation of Standard Solutions

[0059] Standard intermediate solution A of 36 non-phthalate plasticizers: Accurately pipette the reference standards of 36 non-phthalate plasticizers into a 10 mL volumetric flask, dissolve with n-hexane and make up to the mark, mix well, and store in the dark at -18 °C.

[0060] Standard intermediate solution (1 μg / mL) of 36 non-phthalate plasticizers: Accurately pipette 1.0 mL of the standard stock solution of 36 non-phthalate plasticizers into a 10 mL volumetric flask, make up to the mark with n-hexane, mix well, and store in the dark at -18 °C.

[0061] Standard series working solutions of 36 non-phthalate plasticizers: Accurately pipette the standard intermediate solution of 36 non-phthalate plasticizers (1 μg / mL), and serially dilute it with n-hexane to prepare standard series solutions with concentrations of 10, 20, 50, 100, 200, 500, and 1000 ng / mL. Prepare them freshly before use.

[0062] 1.5 Instrument method

[0063] Gas chromatography conditions: After multiple experiments and optimizations, in this study, it was determined that when the following gas chromatography conditions were used, the target compounds achieved the best separation and the best peak shape. Chromatographic column: HP-5MS UI chromatographic column (stationary phase is 5% phenyl + 95% polydimethylsiloxane) (30 m × 0.25 mm × 0.25 μm); Injection port temperature: 250 °C; Transfer line temperature 1: 260 °C, Transfer line temperature 2: 280 °C; Injection volume: 1 μL; Carrier gas: Helium, 1 mL / min; Splitless injection; Programmed temperature rise: Hold at 50 °C for 1 min, raise the temperature to 220 °C at a rate of 20 °C / min, then raise the temperature to 280 °C at a rate of 5 °C / min, and then raise the temperature to 310 °C at a rate of 10 °C / min and hold for 10 min.

[0064] Mass spectrometry conditions: Electron impact ionization source (EI source, 70 eV); Ion source temperature: 280 °C, Transfer line temperature: 280 °C. Solvent delay: 4 min. Acquisition mode: Full scan mode, m / z scan range is 50 - 400, AGC: 1×e 6 , Resolution: 60000.

[0065] Construction of high-resolution mass spectrometry screening database: Inject the standard solution of 36 non-phthalate plasticizers with a mass concentration of 0.5 μg / mL into the instrument and analyze it according to the conditions in Section 2.5. By performing a full scan on the standard substance solution, comparing the mass spectrometry diagram collected by gas chromatography-high resolution after deducting the background with the NIST standard spectral library, and further determining the necessary information such as the target compound, its retention time, and main fragment ions through the fragment ion m / z and its molecular formula. In the TraceFinder-tool-Qual browser, construct a high-resolution database containing 36 compounds such as organophosphates, adipates, sebacates, and phthalates. The details of their retention times, quantitative ions, and qualitative ions are shown in Table 2.

[0066] Table 2 Retention times, quantitative ions, and qualitative ions of 36 non-phthalate plasticizers

[0067]

[0068]

[0069] 2 Results and Discussion

[0070] 2.1 Optimization of Gas Chromatography Conditions

[0071] According to the polarity of the gas chromatography column and the physical and chemical properties of 36 non-phthalate plasticizers, four chromatographic columns, namely HP-5MS (30 m × 0.25 mm × 0.25 μm), HP-5MS UI (30 m × 0.25 mm × 0.25 μm), DB-1MS (30 m × 0.25 mm × 0.25 μm), and DB-1701MS (30 m × 0.25 mm × 0.25 μm), were investigated. And since non-phthalate plasticizers involve many isomers, such as dimethyl terephthalate and dimethyl isophthalate, diphenyl isophthalate and diphenyl terephthalate, and cresyl phosphate (ortho) and cresyl phosphate (meta), their chromatographic retention behaviors and fragment ion m / z are similar, which easily leads to the inseparability of isomers on the chromatographic column. The program temperature rise of the gas chromatography column and gas chromatography can be fully utilized to achieve the separation of their isomers. Therefore, in order to achieve the effective separation and separation efficiency of 36 non-phthalate plasticizers, by investigating different gas chromatography columns and changing the temperature rise program of gas chromatography, the problem that isomers cannot be accurately qualitatively and quantitatively analyzed due to chromatographic inseparability was solved. Finally, HP-5MS UI (30 m × 0.25 mm × 0.25 μm) was selected as the chromatographic column for target separation. The total ion chromatogram of 36 non-phthalate plasticizers is shown in Figure 1 .

[0072] In infant formula samples, due to the complex matrix components, when the temperature rises to 310 °C and is only maintained for 5 min, there will be a large interfering peak around 10 min in the next chromatogram, interfering with the baseline. When maintained for 10 min, this baseline interference can be excluded.

[0073] 2.2 Optimization of Mass Spectrometry Conditions

[0074] The electrostatic field orbitrap mass spectrometer used in this experiment has the characteristics of high resolution, high mass accuracy, high sensitivity, wide dynamic range, and long-term stability. In the high-resolution analysis of gas chromatography-mass spectrometry, 70 eV electrons are used to directly bombard the sample molecules. The 70 eV electron energy is sufficient to ionize most organic molecules and cause fragmentation. And in order to comprehensively and deeply analyze the full-scan spectra of gas chromatography-mass spectrometry in the future, therefore, the full-scan mode (FullMS-SIM) was selected.

[0075] For the qualitative analysis of trace components in complex matrices, resolution plays a crucial role. The level of resolution determines the accuracy of mass numbers. Generally, the higher the resolution, the better it can distinguish substances with similar molecular weights, avoiding false positives. However, the higher the resolution, the lower the scanning speed. Therefore, when determining the mass resolution for scanning, two factors, selectivity and sensitivity, should be considered to ensure sufficient selectivity and collection points. Experiments have found that when the resolution is high (R = 140,000), the scanning speed decreases, resulting in fewer collected points. The obtained peak shapes are difficult to quantify, and in some cases, there are too few points to form a peak. When injecting samples repeatedly, inconsistent results and loss of key information in the mass spectrometry diagram occur, leading to a significant reduction in reproducibility and an increase in the uncertainty of the detection results. When the resolution of the first-stage full scan is R = 60,000, all analytes can be baseline-separated from the interfering substances in the matrix, and the response value is also significantly increased, greatly reducing matrix interference. Therefore, considering both the qualitative and quantitative accuracy of the detection, the resolution of the first-stage full scan is selected as 60,000.

[0076] 2.3 Selection of extraction solvent

[0077] Non-phthalate plasticizers include compounds such as organophosphates, adipates, maleates, and fumarates. There are many types of them, so it is particularly important to select an appropriate extraction solvent. The commonly used extraction solvents in the detection of non-phthalate plasticizers are n-hexane, acetonitrile, and methanol. For different sample matrices, a suitable extraction solvent needs to be selected. In the wine sample matrix, since acetonitrile and methanol are miscible with the wine sample and the wine sample matrix is very clean, after direct extraction with n-hexane, it can be injected into the instrument. Therefore, n-hexane is selected as the extraction solvent. In the vegetable oil sample matrix, due to the complex sample matrix, when n-hexane is used as the extractant, it will be miscible with the vegetable oil sample, and the fat in the vegetable oil will cause serious contamination to the chromatographic system. When methanol is used as the extraction solvent, there are many miscellaneous peaks in its chromatogram, see Figure 2 , which may be due to the relatively high polarity of methanol resulting in more co-extraction. When acetonitrile is used as the extractant, the chromatogram is relatively clean, see Figure 3 , so in the vegetable oil sample matrix, acetonitrile is selected as the extraction solvent.

[0078] In the matrix of milk powder samples, it is necessary to select appropriate solvents to dissolve the milk powder samples and for extraction. First, the extraction solvents n-hexane, methanol, and acetonitrile were investigated. When n-hexane was used as the extraction agent, serious emulsification occurred, resulting in incomplete extraction. When methanol was used as the extraction agent, methanol was miscible with the 20% NaCl solution, and it was not easy to separate methanol and water, and the aqueous phase would cause fatal damage to the chromatographic column. Therefore, in the matrix of infant formula milk powder samples, acetonitrile was selected as the extraction solvent. Then, water, 20% NaCl solution, and saturated NaCl solution were investigated for dissolving the samples. When only water was used to dissolve the samples, the recovery rates of most non-phthalate plasticizers were relatively low, around 70%. When the samples were dissolved with 20% NaCl solution and saturated NaCl solution, the recovery rates of most non-phthalate plasticizers were close to 85%, as shown in Figure 4 . Considering that saturated NaCl might cause incomplete extraction, therefore, 20% NaCl solution was used to dissolve infant formula milk powder samples.

[0079] 2.4 Optimization of the volume of extraction solvent

[0080] The extraction efficiencies were investigated when the volumes of n-hexane added to liquor were 5, 10, 15, and 20 mL respectively. The results are shown in Figure 5 . The results showed that in the liquor matrix samples, when the volume of n-hexane reached 10 mL, the extraction efficiencies of 36 non-phthalate plasticizers had reached equilibrium. Increasing the volume of the extraction solvent further would not change the extraction efficiency. Therefore, considering cost and environmental protection, 10 mL of n-hexane was selected as the extraction condition for liquor matrix samples. The extractions were investigated when the volumes of acetonitrile added to vegetable oil sample matrix were 2, 5, 10, and 15 mL respectively, as shown in Figure 6 . When the volumes of acetonitrile were 2 and 5 mL, the extraction efficiencies were relatively low. When the volume of acetonitrile was 10 mL, the extraction rates of 36 non-phthalate plasticizers had reached equilibrium. Increasing the volume of the extraction solvent further, the concentration changes of the 36 non-phthalate plasticizers were small. Therefore, 10 mL of acetonitrile was selected as the extraction condition for vegetable oil sample matrix. The extractions were investigated when the volumes of acetonitrile added to infant formula milk powder matrix were 2, 5, 10, and 15 mL respectively, as shown in Figure 7 . When the volumes of acetonitrile were 2 and 5 mL, the matrix effects were very strong, and the recovery rates of some compounds could be as high as about 200%. When the volume of acetonitrile was 10 mL, the matrix effect was significantly reduced, and the recovery rates of most non-phthalate plasticizers were reduced to an acceptable level. Increasing the volume of acetonitrile further, the extraction efficiency had reached equilibrium. Therefore, 10 mL of acetonitrile was selected as the extraction condition for infant formula milk powder sample matrix.

[0081] 2.5 Optimization of extraction time

[0082] Since alcoholic beverages and vegetable oil are liquid samples while infant formula is a solid sample, the influence of different extraction times on the extraction efficiency of non-phthalate plasticizers in infant formula was mainly investigated. Under the condition that other conditions remained unchanged, the ultrasonic time was first investigated. The influence of vortex for 5 min followed by ultrasonic for 5 min, vortex for 5 min followed by ultrasonic for 10 min, vortex for 5 min followed by ultrasonic for 20 min, vortex for 5 min followed by ultrasonic for 30 min, vortex for 5 min followed by ultrasonic for 40 min, and vortex for 5 min followed by ultrasonic for 50 min on the extraction efficiency of the analyte was investigated respectively, as shown in Figure 8 . The results showed that after vortex for 5 min and ultrasonic for 30 min, the extraction efficiency had basically reached equilibrium. Moreover, with the increase of time, the concentration of the analyte in the extract did not change significantly. Finally, ultrasonic for 30 min was selected. Then the vortex time was investigated. The influence of vortex for 5 min followed by ultrasonic for 30 min, vortex for 10 min followed by ultrasonic for 30 min, vortex for 15 min followed by ultrasonic for 30 min, and vortex for 20 min followed by ultrasonic for 30 min on the extraction efficiency of the analyte was investigated respectively, as shown in Figure 9 . The results showed that after vortex for 5 min and ultrasonic for 30 min, the extraction efficiency had basically reached equilibrium. Moreover, with the increase of time, the concentration of the analyte in the extract did not change significantly. In summary, vortex for 5 min followed by ultrasonic for 30 min was finally selected.

[0083] 2.6 Investigation of purification methods

[0084] Since the matrixes of vegetable oil and infant formula are likely to interfere with the analyte, it is necessary to purify the sample extract. According to the properties of 36 non-phthalate plasticizers, the QuEChERS method was mainly considered for sample purification. Currently, the adsorbents used in QuEChERS mainly include PSA, Silica, C 18 , and GCB. PSA has an adsorption effect on polar substances and can remove the interference of sugars, organic acids, etc.; Silica has an adsorption effect on polar substances; C 18It has an adsorption effect on non-polar substances and can remove interferences such as lipids and sterols; GCB can remove pigments and non-polar substances in the sample. According to preliminary experiments, it was found that GCB has a strong adsorption effect on non-phthalate compounds, so GCB is not considered as an adsorbent. In rapeseed oil, with other conditions unchanged, different ratios of Silica + PSA mixtures were first considered: 100mg Silica + 100mg PSA, 200mg Silica + 200mg PSA, 300mg Silica + 300mg PSA, 400mg Silica + 400mg PSA, 500mg Silica + 500mg PSA, 600mg Silica + 600mg PSA, 700mg Silica + 700mg PSA, see Figure 10 . The results showed that when 500mg Silica + 500mg PSA was mixed, the purification effect of most of the 36 non-phthalate plasticizers was good, and there was less interference in the chromatogram. In particular, after rapeseed oil was directly extracted with acetonitrile and injected into the machine, see Figure 11 , at a retention time of 16.94 min, there was a large interference peak, but after purification with Silica + PSA, the peak area response of this interference peak decreased significantly, see Figure 12 . Then it was investigated whether it was necessary to add C 18 , 10, 20, 30, 40, 50 and 60 mg. After investigation, when 50mg C 18 was added, the peak shapes of some compounds such as dimethyl azelate, dibutyl fumarate, dibutyl itaconate, dimethyl sebacate, diethyl azelate, and dibutyl adipate became more symmetrical and no longer tailed. In the matrix of infant formula milk powder, the same ratio of Silica + PSA was mixed, see Figure 13 . The results showed that when 500mg Silica + 500mg PSA was mixed, the purification effect of most of the 36 non-phthalate plasticizers was good. Then it was investigated whether it was necessary to add C 18 , 10, 20, 30, 40, 50 and 60 mg. After investigation, when 50mg C 18 was added, the peak shapes of its compounds such as dimethyl azelate, dibutyl fumarate, dibutyl itaconate, dimethyl sebacate, diethyl azelate, and dibutyl adipate did not change much. However, considering that the milk powder matrix also contains a large amount of oil, to be consistent with vegetable oil, 50mg C 18 was also added. And when the vegetable oil and the matrix samples of infant formula milk powder were purified by QuEChERS, the service life of the chromatographic column was compared between the preliminary experiment without purification and the experiment after purification. The service life of the chromatographic column was significantly extended.

[0085] 3 Optimized Pretreatment Method

[0086] 3.1 Alcohol

[0087] Accurately weigh 1.0g of the sample (accurate to 0.001g) into a 25mL stoppered ground-mouth glass tube, accurately add 10mL of n-hexane, vortex for 5min, ultrasonically extract for 30min, and centrifuge at 1000r / min for 5min. Take 2.5mL of the supernatant into a 10mL glass nitrogen blowpipe, blow it to near dryness in a 40℃ water bath, accurately make up to 1.0mL with n-hexane, vortex and mix, and provide GC-Q / Orbitrap HRMS analysis.

[0088] 3.2 Vegetable oil

[0089] Accurately weigh 0.5 g (accurate to 0.001 g) of the sample into a 25 mL stoppered ground-mouth glass tube, accurately add 10 mL of acetonitrile, vortex for 5 min, ultrasonically extract for 30 min, and centrifuge at 1000 r / min for 5 min. The supernatant is to be purified.

[0090] Pipette 7 mL of supernatant and add it to a flask containing 500 mg silica, 500 mg PSA and 50 mg C. 18 Place in a 10mL glass tube, vortex mix for 5min, and centrifuge at 1000r / min for 5min. Accurately pipette 5mL of supernatant into a 10mL glass nitrogen blowpipe, blow to nearly dryness with nitrogen in a 40℃ water bath, accurately dilute to 1.0mL with n-hexane, vortex mix, and prepare for GC-Q / Orbitrap HRMS analysis.

[0091] 3.3 Milk powder samples

[0092] Accurately weigh 0.5g of the sample (accurate to 0.001g) into a 25mL stoppered ground-mouth glass tube, add 2mL of 20% NaCl solution, then accurately add 10mL of acetonitrile, vortex for 5min, ultrasonically extract for 30min, add 1g of NaCl, mix well, and centrifuge at 1000r / min for 5min. The supernatant is to be purified.

[0093] Pipette 7 mL of supernatant and add it to a flask containing 500 mg silica, 500 mg PSA and 50 mg C. 18 Place in a 10mL glass tube, vortex mix for 5min, and centrifuge at 1000r / min for 5min. Accurately pipette 5mL of supernatant into a 10mL glass nitrogen blowpipe, blow to nearly dryness with nitrogen in a 40℃ water bath, accurately dilute to 1.0mL with n-hexane, vortex mix, and prepare for GC-Q / Orbitrap HRMS analysis.

[0094] 3.4 Blank test

[0095] Except for not adding the test sample, the determination steps in 2.5.1 - 2.5.3 are followed. (The blank is strictly controlled throughout the test process).

[0096] 3.5 Evaluation method of matrix effect (ME)

[0097] In this paper, the matrix effect of non - phthalate plasticizers is evaluated according to the formula Matrix Effect (%) = B / A × 100% (A: the slope of the calibration curve of the analyte in pure solvent, B: the slope of the calibration curve of the analyte added with the same content in the sample matrix). When its value is between 0.8 and 1.2, the matrix effect can be ignored. The ME values of 36 non - phthalate plasticizers in three matrices (liquor, vegetable oil, infant formula milk powder) of this method are all between 0.90 and 1.15, see Figures 14 to 16 . Therefore, in this study, the influence of the matrix effect is ignored, and the standard curve is prepared with n - hexane.

[0098] 4 Investigation of quantitative methodology

[0099] 4.1 Sample source

[0100] All samples were purchased from local supermarkets and screened for background.

[0101] 4.2 Linear range

[0102] For the standard working curves of 36 non - phthalate plasticizers, in the concentration range of 10 - 1000 ng / mL, the standard curve r is greater than 0.999, as shown in Table 2 - 3, meeting the requirement in GB / T 27404 - 2008 that r for calibration curve confirmation should not be lower than 0.99.

[0103] 4.3 Detection limit and quantification limit

[0104] The detection limit is obtained by adding different amounts of the mixed standard solution of 36 non - phthalate plasticizers to blank white liquor, rapeseed oil, and infant formula milk powder, and taking the added amount corresponding to the signal - to - noise ratio S / N ≥ 3 of the qualitative ion and quantitative ion as the detection limit of the target substance. The quantification limit is obtained by adding different amounts of the mixed standard solution of 36 non - phthalate plasticizers to blank white liquor, rapeseed oil, and infant formula milk powder, and taking the added amount corresponding to the signal - to - noise ratio S / N ≥ 10 of the qualitative ion and quantitative ion as the quantification limit of the target substance. The detection limits and quantification limits of 36 non - phthalate plasticizers are shown in Table 3 specifically.

[0105] Table 3 Linear range, detection limit and quantification limit of 36 non - phthalate plasticizers

[0106]

[0107]

[0108] 4.4 Recovery Rate and Precision

[0109] According to GB / T 27404-2008 "Code for Laboratory Quality Control - Physical and Chemical Tests of Foods", according to the method text, weigh the matrix samples of empty liquor, soybean oil, and milk powder, conduct three-level spiking tests according to the limit of quantification, twice the limit of quantification, and ten times the limit of quantification. Do 6 parallels for each level, and conduct the determination according to the operation steps specified in the method to examine the recovery rate of the method. The data are shown in Tables 4, 5, and 6 respectively. As can be seen from Table 4, in the liquor samples, the spiking recovery rate ranges of triethyl phosphate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg are respectively: 60.5% - 69.9%, 62.9% - 67.2%, 64.1% - 65.7%, and the relative standard deviations are: 6.95%, 2.90%, 1.19%. The spiking recovery rate ranges of diethyl maleate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg are respectively 61.4% - 69.6%, 60.2% - 66.2%, 63.8% - 69.8%, and the relative standard deviations are: 5.01%, 3.49%, 3.69%. The spiking recovery rate ranges of 2-ethylhexyl acrylate at the concentration points of 0.04 mg / kg, 0.08 mg / kg, and 0.40 mg / kg are respectively 75.7% - 98.1%, 78.2% - 86.9%, 68.5% - 73.2%, and the relative standard deviations are: 9.31%, 4.00%, 2.30%. The spiking recovery rate ranges of dimethyl adipate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg are respectively 72.8% - 77.2%, 75.3% - 83.3%, 72.9% - 77.5%, and the relative standard deviations are: 2.29%, 3.51%, 2.30%. The spiking recovery rate ranges of diethyl adipate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg are respectively 86.3% - 91.9%, 72.8% - 80.6%, 68.1% - 74.8%, and the relative standard deviations are: 2.57%, 3.66%, 3.29%. The spiking recovery rate ranges of diisobutyl fumarate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg are respectively 80.0% - 83.9%, 84.5% - 89.1%, 71.9% - 88.3%, and the relative standard deviations are: 2.48%, 2.08%, 7.26%. The spiking recovery rate ranges of dimethyl terephthalate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg are respectively 81.5% - 84.4%, 76.1% - 81.5%, 75.1% - 80.4%, and the relative standard deviations are: 1.50%, 2.49%, 2.39%. The spiking recovery rate ranges of dimethyl isophthalate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg are respectively 80.4% - 86.3%, 75.2% - 79.5%, 74.0% - 79.6%, with relative standard deviations of: 2.45%, 1.91%, 2.77%. The spiked recovery ranges of dibutyl maleate at concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were 84.6% - 95.3%, 91.6% - 94.2%, and 84.4% - 92.5% respectively, with relative standard deviations of: 4.58%, 1.16%, 4.11%. The spiked recovery ranges of dimethyl azelate at concentration points of 0.04 mg / kg, 0.08 mg / kg, and 0.40 mg / kg were 85.5% - 92.7%, 81.0% - 91.4%, and 91.0% - 98.6% respectively, with relative standard deviations of: 2.95%, 4.48%, 3.31%. The spiked recovery ranges of dibutyl fumarate at concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were 90.1% - 100.1%, 104.2% - 110.6%, and 96.2% - 103.1% respectively, with relative standard deviations of: 4.68%, 1.95%, 2.73%. The spiked recovery ranges of dibutyl itaconate at concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were 87.3% - 100.6%, 106.4% - 108.2%, and 95.7% - 104.7% respectively, with relative standard deviations of: 6.07%, 1.01%, 3.46%. The spiked recovery ranges of dimethyl sebacate at concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were 96.4% - 104.5%, 87.7% - 100.2%, and 96.5% - 103.5% respectively, with relative standard deviations of: 2.97%, 4.36%, 3.01%. The spiked recovery ranges of tributyl phosphate at concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were 87.6% - 105.6%, 104.8% - 116.6%, and 105.8% - 112.5% respectively, with relative standard deviations of: 6.79%, 3.68%, 3.27%. The spiked recovery ranges of diethyl azelate at concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were 103.2% - 114.0%, 85.4% - 94.9%, and 96.9% - 105.5% respectively, with relative standard deviations of: 4.08%, 3.82%, 3.36%. The spiked recovery ranges of dibutyl adipate at concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were 99.6% - 111.9%, 107.8% - 111.7%, and 105.2% - 117.5% respectively, with relative standard deviations of: 4.11%, 1.16%, 3.99%. The spiked recovery ranges of diethyl sebacate at concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.The spiked recovery rates at the concentration points of 20 mg / kg were in the ranges of 90.9% - 106.2%, 106.8% - 115.0%, and 104.0% - 113.1% respectively, and the relative standard deviations were 6.46%, 2.36%, and 3.14%. The spiked recovery rates of diethylhexyl maleate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were in the ranges of 99.6% - 114.0%, 96.4% - 113.9%, and 105.4% - 117.5% respectively, and the relative standard deviations were 4.98%, 5.85%, and 4.01%. The spiked recovery rates of dibutyl sebacate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were in the ranges of 79.9% - 95.7%, 96.2% - 106.8%, and 104.2% - 112.2% respectively, and the relative standard deviations were 5.83%, 3.83%, and 2.56%. The spiked recovery rates of bis(2-ethylhexyl) itaconate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were in the ranges of 108.7% - 115.8%, 99.9% - 114.7%, and 102.1% - 116.6% respectively, and the relative standard deviations were 3.39%, 6.39%, and 5.47%. The spiked recovery rates of bis(2-ethylhexyl) fumarate at the concentration points of 0.04 mg / kg, 0.08 mg / kg, and 0.40 mg / kg were in the ranges of 97.3% - 109.8%, 100.3% - 109.9%, and 103.1% - 112.8% respectively, and the relative standard deviations were 4.10%, 3.67%, and 3.68%. The spiked recovery rates of bis(2-ethylhexyl) adipate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were in the ranges of 94.6% - 107.7%, 96.9% - 105.3%, and 108.7% - 114.1% respectively, and the relative standard deviations were 5.22%, 3.24%, and 1.84%. The spiked recovery rates of triphenyl phosphate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were in the ranges of 91.3% - 101.6%, 100.6% - 107.1%, and 90.8% - 108.9% respectively, and the relative standard deviations were 3.78%, 2.57%, and 6.30%. The spiked recovery rates of bis(2-ethylhexyl) phenyl phosphate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were in the ranges of 98.9% - 105.4%, 101.6% - 114.9%, and 101.9% - 111.0% respectively, and the relative standard deviations were 3.08%, 5.04%, and 3.41%. The spiked recovery rates of tris(2-ethylhexyl) phosphate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were in the ranges of 88.6% - 106.3%, 97.3% - 113.6%, 100.6% - 117.8%, the relative standard deviations are: 7.37%, 6.07%, 7.00%. The spiked recovery ranges of dioctyl adipate at concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg are 94.2% - 110.6%, 96.8% - 109.9%, 101.8 - 114.2% respectively, and the relative standard deviations are: 5.64%, 5.16%, 4.56%. The spiked recovery ranges of tricresyl phosphate at concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg are 88.0% - 99.7%, 100.1% - 112.8%, 98.4% - 118.6% respectively, and the relative standard deviations are: 4.58%, 3.96%, 8.23%. The spiked recovery ranges of m-cresyl phosphate at concentration points of 0.04 mg / kg, 0.08 mg / kg, and 0.40 mg / kg are 94.6% - 106.8%, 98.1% - 103.8%, 101.1% - 108.0% respectively, and the relative standard deviations are: 4.29%, 2.17%, 2.58%. The spiked recovery ranges of bis(2-ethylhexyl) isophthalate at concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg are 104.3% - 113.1%, 97.8% - 112.0%, 102.8% - 118.3% respectively, and the relative standard deviations are: 3.23%, 4.69%, 6.09%. The spiked recovery ranges of bis(2-ethylhexyl) azelate at concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg are 86.0% - 104.3%, 96.7% - 110.4%, 101.6% - 116.0% respectively, and the relative standard deviations are: 6.83%, 5.35%, 5.11%. The spiked recovery ranges of diphenyl isophthalate at concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg are 102.8% - 112.3%, 92.2% - 104.7%, 103.1% - 115.8% respectively, and the relative standard deviations are: 4.09%, 5.59%, 4.68%. The spiked recovery ranges of diphenyl terephthalate at concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg are 104.6% - 116.8%, 96.0% - 101.0%, 100.4% - 103.9% respectively, and the relative standard deviations are: 4.33%, 3.20%, 2.26%. The spiked recovery ranges of bis(2-ethylhexyl) terephthalate at concentration points of 0.04 mg / kg, 0.08 mg / kg, and 0.40 mg / kg are 102.8% - 112.5%, 98.0% - 103.0%, 102.3% - 112.3% respectively, and the relative standard deviations are: 3.23%, 1.63%, 3.43%. The spiked recovery rates of tris(p-tolyl) phosphate at the concentration points of 0.04 mg / kg, 0.08 mg / kg, and 0.40 mg / kg were in the ranges of 92.8% - 103.6%, 98.1% - 103.6%, and 96.7% - 107.2% respectively, and the relative standard deviations were 3.99%, 2.23%, and 4.11%. The spiked recovery rates of bis(2-ethylhexyl) sebacate at the concentration points of 0.04 mg / kg, 0.08 mg / kg, and 0.40 mg / kg were in the ranges of 89.5% - 105.7%, 96.4% - 103.7%, and 97.4% - 105.4% respectively, and the relative standard deviations were 5.59%, 2.60%, and 2.82%. The spiked recovery rates of di-n-octyl isophthalate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were in the ranges of 86.8% - 106.2%, 93.5% - 103.2%, and 102.1% - 114.7% respectively, and the relative standard deviations were 7.48%, 4.15%, and 3.94%. All of them met the requirements of recovery rate and precision in Standard GB / T 27404-2008.

[0110] As can be seen from Table 5, in the soybean oil samples, the spiked recovery rates of triethyl phosphate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were in the ranges of 82.6% - 94.1%, 80.9% - 94.5%, and 71.9% - 88.2% respectively, and the relative standard deviations were 4.56%, 6.32%, and 6.91% respectively. The spiked recovery rates of diethyl maleate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were in the ranges of 83.8% - 99.6%, 81.7% - 104.4%, and 72.3% - 82.3% respectively, and the relative standard deviations were 5.93%, 9.58%, and 5.53% respectively. The spiked recovery rates of 2-ethylhexyl acrylate at the concentration points of 0.04 mg / kg, 0.08 mg / kg, and 0.40 mg / kg were in the ranges of 85.2% - 97.7%, 90.5% - 99.2%, and 67.2% - 86.8% respectively, and the relative standard deviations were 5.30%, 4.41%, and 9.84% respectively. The spiked recovery rates of dimethyl adipate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were in the ranges of 91.6% - 107.2%, 82.2% - 94.9%, and 71.1% - 86.6% respectively, and the relative standard deviations were 6.25%, 5.96%, and 6.63% respectively. The spiked recovery rates of diethyl adipate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were in the ranges of 94.2% - 108.3%, 85.4% - 94.9%, and 78.7% - 88.4% respectively, and the relative standard deviations were 4.57%, 4.40%, and 5.60% respectively. The spiked recovery rates of diisobutyl fumarate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were in the ranges of 104.8% - 114.7%, 99.7% - 107.3%, and 87.5% - 94.4% respectively, and the relative standard deviations were 3.87%, 3.58%, and 3.01% respectively. The spiked recovery rates of dimethyl terephthalate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were in the ranges of 95.2% - 116.0%, 91.5% - 108.3%, and 82.0% - 97.0% respectively, and the relative standard deviations were 7.71%, 6.32%, and 6.48% respectively. The spiked recovery rates of dimethyl isophthalate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were in the ranges of 100.2% - 116.6%, 92.2% - 104.8%, and 80.6% - 96.8% respectively, and the relative standard deviations were 5.15%, 4.65%, and 7.45% respectively. The spiked recovery rates of dibutyl maleate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were in the ranges of 96.1% - 109.6%, 93.0% - 108.1%, and 88.5% - 101.3%, with relative standard deviations of 5.63%, 6.31%, and 5.17%. The spiked recovery ranges of dimethyl azelate at concentration points of 0.04 mg / kg, 0.08 mg / kg, and 0.40 mg / kg were 85.4% - 107.2%, 85.4% - 107.9%, and 85.0% - 96.9% respectively, with relative standard deviations of 9.43%, 9.96%, and 5.01%. The spiked recovery ranges of dibutyl fumarate at concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were 101.2% - 114.6%, 89.5% - 108.6%, and 88.6% - 97.4% respectively, with relative standard deviations of 4.40%, 7.32%, and 3.66%. The spiked recovery ranges of dibutyl itaconate at concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were 100.6% - 109.8%, 97.1% - 107.4%, and 90.9% - 102.1% respectively, with relative standard deviations of 3.26%, 4.01%, and 4.28%. The spiked recovery ranges of dimethyl sebacate at concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were 96.3% - 107.8%, 98.3% - 108.9%, and 88.6% - 103.5% respectively, with relative standard deviations of 4.19%, 5.48%, and 5.53%. The spiked recovery ranges of tributyl phosphate at concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were 94.2% - 114.6%, 92.4% - 105.8%, and 89.1% - 102.1% respectively, with relative standard deviations of 6.72%, 5.57%, and 5.21%. The spiked recovery ranges of diethyl azelate at concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were 99.6% - 116.0%, 89.5% - 104.5%, and 90.5% - 107.0% respectively, with relative standard deviations of 5.60%, 5.85%, and 5.80%. The spiked recovery ranges of dibutyl adipate at concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were 100.6% - 110.1%, 96.8% - 108.6%, and 92.7% - 105.7% respectively, with relative standard deviations of 3.88%, 4.30%, and 4.56%. The spiked recovery ranges of diethyl sebacate at concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were 104.7% - 114.9%, 95.8% - 105.3%, and 95.7% - 109.7% respectively, with relative standard deviations of 3.44%, 4.48%, and 5.22%. The spiked recovery ranges of di(2-ethylhexyl) maleate at concentration points of 0.02 mg / kg, 0.04 mg / kg, 0.The spiked recovery rate ranges at the concentration points of 20 mg / kg are 98.3% - 114.8%, 98.2% - 105.2%, 85.3% - 95.4% respectively, and the relative standard deviations are 6.08%, 2.81%, 4.35%. The spiked recovery rate ranges of dibutyl sebacate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, 0.20 mg / kg are 98.6% - 115.2%, 87.0% - 109.0%, 87.9% - 99.1% respectively, and the relative standard deviations are 6.22%, 7.88%, 4.76%. The spiked recovery rate ranges of bis(2-ethylhexyl) itaconate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, 0.20 mg / kg are 92.5% - 100.6%, 90.7% - 98.3%, 81.1% - 88.8% respectively, and the relative standard deviations are 5.19%, 3.15%, 3.34%. The spiked recovery rate ranges of bis(2-ethylhexyl) fumarate at the concentration points of 0.04 mg / kg, 0.08 mg / kg, 0.40 mg / kg are 70.4% - 75.8%, 77.3% - 87.3%, 65.6% - 69.2% respectively, and the relative standard deviations are 2.90%, 4.25%, 2.36%. The spiked recovery rate ranges of bis(2-ethylhexyl) adipate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, 0.20 mg / kg are 103.5% - 114.9%, 95.2% - 112.1%, 81.5% - 91.5% respectively, and the relative standard deviations are 3.58%, 5.85%, 4.37%. The spiked recovery rate ranges of triphenyl phosphate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, 0.20 mg / kg are 98.2% - 115.6%, 94.0% - 106.1%, 80.1% - 98.4% respectively, and the relative standard deviations are 5.83%, 4.72%, 8.49%. The spiked recovery rate ranges of bis(2-ethylhexyl) phenyl phosphate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, 0.20 mg / kg are 103.4% - 113.7%, 96.3% - 104.6%, 88.8% - 102.2% respectively, and the relative standard deviations are 3.51%, 3.07%, 4.86%. The spiked recovery rate ranges of tris(2-ethylhexyl) phosphate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, 0.20 mg / kg are 81.7% - 93.7%, 82.4% - 89.3%, 71.9% - 77.0% respectively, and the relative standard deviations are 6.11%, 3.19%, 2.83%. The spiked ranges of dioctyl adipate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, 0.20 mg / kg are 83.3% - 92.2%, 70.8% - 87.7%, 73.8% - 79.6% respectively, and the relative standard deviations are 4.13%, 9.25%, 2.97%. The spiked recovery ranges of cresyl phosphate at concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg are 97.5% - 113.6%, 97.4% - 114.05, and 81.0% - 89.8% respectively, and the relative standard deviations are 6.09%, 6.64%, and 5.92%. The spiked recovery ranges of m-cresyl phosphate at concentration points of 0.04 mg / kg, 0.08 mg / kg, and 0.40 mg / kg are 93.0% - 114.2%, 95.1% - 107.1%, and 84.4% - 108.4% respectively, and the relative standard deviations are 7.35%, 3.93%, and 8.42%. The spiked recovery ranges of bis(2-ethylhexyl) isophthalate at concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg are 100.8% - 110.8%, 96.8% - 108.9%, and 86.0% - 95.2% respectively, and the relative standard deviations are 4.24%, 3.89%, and 3.78%. The spiked recovery ranges of bis(2-ethylhexyl) azelate at concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg are 88.9% - 109.1%, 90.1% - 95.8%, and 73.7% - 85.6% respectively, and the relative standard deviations are 7.25%, 2.66%, and 5.29%. The spiked recovery ranges of diphenyl isophthalate at concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg are 99.9% - 115.6%, 101.7% - 111.8%, and 88.8% - 110.0% respectively, and the relative standard deviations are 6.48%, 3.89%, and 9.88%. The spiked recovery ranges of diphenyl terephthalate at concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg are 103.5% - 113.3%, 94.9% - 111.3%, and 89.3% - 110.2% respectively, and the relative standard deviations are 4.09%, 6.12%, and 8.58%. The spiked recovery ranges of bis(2-ethylhexyl) terephthalate at concentration points of 0.04 mg / kg, 0.08 mg / kg, and 0.40 mg / kg are 84.3% - 106.1%, 93.0% - 106.1%, and 85.6% - 105.3% respectively, and the relative standard deviations are 8.65%, 5.93%, and 9.71%. The spiked recovery ranges of tri-p-tolyl phosphate at concentration points of 0.04 mg / kg, 0.08 mg / kg, and 0.40 mg / kg are 97.2% - 111.5%, 98.3% - 109.7%, and 89.3% - 106.4% respectively, and the relative standard deviations are 5.04%, 3.97%, and 5.77%. The spiked recovery ranges of bis(2-ethylhexyl) sebacate at concentration points of 0.04 mg / kg, 0.08 mg / kg, 0.The spiked recovery rate ranges at the concentration points of 40 mg / kg were 95.8% - 103.1%, 89.0% - 95.9%, and 70.4% - 77.6% respectively, and the relative standard deviations were 3.28%, 2.99%, and 3.92%. The spiked recovery rate ranges of di-n-octyl phthalate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were 84.9% - 98.6%, 70.4% - 77.2%, and 61.4% - 68.9% respectively, and the relative standard deviations were 5.94%, 3.94%, and 5.08%. All of them met the requirements of recovery rate and precision in the standard GB / T 27404 - 2008.

[0111] As can be seen from Table 6, in the infant formula milk powder samples, the spiked recovery rates of triethyl phosphate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were in the ranges of 95.6% - 108.3%, 97.9% - 108.2%, and 84.2% - 94.9% respectively, and the relative standard deviations were 5.92%, 4.01%, and 5.37% respectively. The spiked recovery rate ranges of diethyl maleate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were 85.1% - 90.0%, 82.9% - 97.8%, and 73.7% - 83.8% respectively, and the relative standard deviations were 2.02%, 8.21%, and 4.49% respectively. The spiked recovery rate ranges of 2-ethylhexyl acrylate at the concentration points of 0.04 mg / kg, 0.08 mg / kg, and 0.40 mg / kg were 78.3% - 87.3%, 67.2% - 78.4%, and 64.1% - 74.5% respectively, and the relative standard deviations were 4.01%, 6.95%, and 6.34% respectively. The spiked recovery rate ranges of dimethyl adipate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were 94.2% - 106.1%, 91.9% - 104.6%, and 88.0% - 95.6% respectively, and the relative standard deviations were 4.89%, 7.15%, and 3.25% respectively. The spiked recovery rate ranges of diethyl adipate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were 100.2% - 109.4%, 92.3% - 111.9%, and 88.4% - 97.4% respectively, and the relative standard deviations were 3.12%, 6.82%, and 3.76% respectively. The spiked recovery rate ranges of diisobutyl fumarate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were 102.4% - 109.1%, 91.3% - 111.4%, and 91.0% - 103.9% respectively, and the relative standard deviations were 2.36%, 8.26%, and 5.28% respectively. The spiked recovery rate ranges of dimethyl terephthalate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were 105.1% - 115.0%, 97.6% - 114.3%, and 93.5% - 107.6% respectively, and the relative standard deviations were 3.73%, 5.87%, and 5.97% respectively. The spiked recovery rate ranges of dimethyl isophthalate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were 95.2% - 113.2%, 94.3% - 113.9%, and 93.7% - 110.0% respectively, and the relative standard deviations were 6.93%, 7.26%, and 6.81% respectively. The spiked recovery rate ranges of dibutyl maleate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were 96.6% - 114.1%, 97.5% - 113.9%, 94.9% - 103.7%, with relative standard deviations of: 5.73%, 5.98%, 4.69%. The spiked recovery ranges of dimethyl azelate at concentration points of 0.04 mg / kg, 0.08 mg / kg, and 0.40 mg / kg were 92.1% - 104.3%, 82.5% - 93.1%, 76.4% - 86.2% respectively, with relative standard deviations of: 5.25%, 4.13%, 5.27%. The spiked recovery ranges of dibutyl fumarate at concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were 99.9% - 114.4%, 97.0% - 112.2%, 84.2% - 107.3% respectively, with relative standard deviations of: 5.61%, 5.78%, 9.64%. The spiked recovery ranges of dibutyl itaconate at concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were 97.1% - 112.1%, 91.0% - 109.1%, 82.9% - 99.1% respectively, with relative standard deviations of: 5.93%, 6.85%, 7.32%. The spiked recovery ranges of dimethyl sebacate at concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were 104.7% - 114.4%, 91.4% - 116.0%, 81.8% - 103.9% respectively, with relative standard deviations of: 2.93%, 9.74%, 9.05%. The spiked recovery ranges of tributyl phosphate at concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were 103.2% - 113.0%, 94.4% - 112.8%, 83.7% - 108.8% respectively, with relative standard deviations of: 3.25%, 8.01%, 9.87%. The spiked recovery ranges of diethyl azelate at concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were 103.4% - 116.7%, 95.5% - 116.2%, 81.9% - 98.0% respectively, with relative standard deviations of: 4.40%, 7.76%, 6.28%. The spiked recovery ranges of dibutyl adipate at concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were 101.1% - 114.1%, 98.1% - 114.7%, 81.9% - 93.2% respectively, with relative standard deviations of: 5.53%, 7.25%, 4.67%. The spiked recovery ranges of diethyl sebacate at concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were 98.8% - 114.8%, 88.2% - 113.5%, 88.2% - 100.7% respectively, with relative standard deviations of: 5.56%, 9.26%, 4.99%. The spiked recovery ranges of di(2-ethylhexyl) maleate at concentration points of 0.02 mg / kg, 0.04 mg / kg, 0.The spiked recovery rates at the concentration points of 20 mg / kg were in the ranges of 96.3% - 112.4%, 99.6% - 111.3%, and 88.0% - 99.1% respectively, and the relative standard deviations were 6.10%, 5.93%, and 4.35%. The spiked recovery rates of dibutyl sebacate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were in the ranges of 95.1% - 113.0%, 95.4% - 113.8%, and 92.0% - 105.0% respectively, and the relative standard deviations were 7.26%, 7.43%, and 4.64%. The spiked recovery rates of bis(2-ethylhexyl) itaconate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were in the ranges of 92.9% - 115.1%, 88.2% - 108.5%, and 81.7% - 94.8% respectively, and the relative standard deviations were 8.87%, 7.53%, and 5.60%. The spiked recovery rates of bis(2-ethylhexyl) fumarate at the concentration points of 0.04 mg / kg, 0.08 mg / kg, and 0.40 mg / kg were in the ranges of 93.9% - 111.4%, 96.1% - 104.7%, and 83.6% - 96.4% respectively, and the relative standard deviations were 7.42%, 3.39%, and 5.12%. The spiked recovery rates of bis(2-ethylhexyl) adipate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were in the ranges of 84.8% - 97.9%, 93.0% - 106.4%, and 94.0% - 102.8% respectively, and the relative standard deviations were 4.86%, 5.56%, and 3.75%. The spiked recovery rates of triphenyl phosphate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were in the ranges of 97.3% - 112.6%, 95.0% - 111.9%, and 87.7% - 100.3% respectively, and the relative standard deviations were 5.62%, 7.64%, and 4.33%. The spiked recovery rates of bis(2-ethylhexyl) phenyl phosphate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were in the ranges of 99.4% - 113.1%, 95.2% - 113.9%, and 88.8% - 102.9% respectively, and the relative standard deviations were 4.59%, 6.58%, and 5.03%. The spiked recovery rates of tris(2-ethylhexyl) phosphate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were in the ranges of 94.5% - 112.0%, 92.3% - 115.5%, and 83.6% - 97.9% respectively, and the relative standard deviations were 5.98%, 9.43%, and 6.64%. The spiked recovery rates of di-n-octyl adipate at the concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were in the ranges of 105.7% - 115.0%, 105.5% - 116.5%, and 87.8% - 101.8%, with relative standard deviations of 3.09%, 3.39%, and 5.42%. The spiked recovery ranges of cresyl phosphate at concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were 94.4% - 109.6%, 106.9% - 116.1%, and 94.0% - 100.3% respectively, with relative standard deviations of 5.48%, 3.36%, and 5.53%. The spiked recovery ranges of m-cresyl phosphate at concentration points of 0.04 mg / kg, 0.08 mg / kg, and 0.40 mg / kg were 105.2% - 108.5%, 93.5% - 106.9%, and 91.1% - 96.4% respectively, with relative standard deviations of 3.62%, 4.79%, and 2.14%. The spiked recovery ranges of bis(2-ethylhexyl) isophthalate at concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were 97.5% - 109.7%, 105.5% - 114.8%, and 81.0% - 89.9% respectively, with relative standard deviations of 4.49%, 2.91%, and 4.45%. The spiked recovery ranges of bis(2-ethylhexyl) azelate at concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were 107.2% - 112.0%, 98.9% - 116.5%, and 93.9% - 110.8% respectively, with relative standard deviations of 2.00%, 6.93%, and 5.90%. The spiked recovery ranges of diphenyl isophthalate at concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were 105.9% - 116.6%, 95.7% - 114.8%, and 91.8% - 105.6% respectively, with relative standard deviations of 3.67%, 5.83%, and 5.29%. The spiked recovery ranges of diphenyl terephthalate at concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg were 102.4% - 112.9%, 95.1% - 110.2%, and 101.2% - 113.8% respectively, with relative standard deviations of 3.60%, 5.23%, and 4.33%. The spiked recovery ranges of bis(2-ethylhexyl) terephthalate at concentration points of 0.04 mg / kg, 0.08 mg / kg, and 0.40 mg / kg were 96.7% - 112.1%, 94.4% - 100.4%, and 90.6% - 100.9% respectively, with relative standard deviations of 5.80%, 2.15%, and 4.15%. The spiked recovery ranges of tri-p-tolyl phosphate at concentration points of 0.04 mg / kg, 0.08 mg / kg, and 0.40 mg / kg were 105.1% - 116.5%, 96.0% - 110.5%, and 92.3% - 99.3% respectively, with relative standard deviations of 4.01%, 4.87%, and 2.82%. The spiked recovery ranges of bis(2-ethylhexyl) sebacate at 0.The spiked recovery rate ranges of the concentration points of 0.04 mg / kg, 0.08 mg / kg, and 0.40 mg / kg are 85.3% - 101.9%, 94.6% - 97.6%, and 80.1% - 86.6% respectively, and the relative standard deviations are 7.70%, 1.26%, and 2.89%. The spiked recovery rate ranges of the concentration points of 0.02 mg / kg, 0.04 mg / kg, and 0.20 mg / kg for di-n-octyl phthalate are 101.1% - 114.1%, 95.5% - 111.7%, and 82.4% - 90.1% respectively, and the relative standard deviations are 4.55%, 5.69%, and 4.93%. All of them meet the requirements of the recovery rate and precision in GB / T 27404-2008.

[0112] Table 4 Recovery rate results of 36 non-phthalate plasticizers in liquor samples

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[0117] Table 5 Recovery rate results of 36 non-phthalate plasticizers in vegetable oil samples

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[0123] Table 6 Recovery rate results of 36 non-phthalate plasticizers in infant formula milk powder samples

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[0127]

[0128] 5. Summary

[0129] 5.1. Establish a screening database for non-phthalate plasticizers through the structural analysis of unknown substances in samples.

[0130] 5.2. Establish a precise identification and determination method for 36 non-phthalate plasticizers in typical processed foods (liquors, edible vegetable oils, infant formula milk powder, and foods) by optimizing the extraction solvent, comparing QuERChERS purification powders, and optimizing the gas phase and mass spectrometry conditions, and verify it through methodology.

[0131] 5.3. Successfully apply this method to the risk monitoring of non-phthalate plasticizers in more than 100 batches of samples such as liquors, edible vegetable oils, infant formula milk powder, and foods.

Claims

1. A rapid screening method for non-phthalate plasticizers in processed foods, characterized by: It uses gas chromatography-quadrupole / electrostatic field orbital trap high-resolution mass spectrometry to detect 36 non-phthalate plasticizers; The gas chromatography conditions were as follows: chromatographic column: HP-5MS UI chromatographic column (stationary phase: 5% phenyl + 95% polydimethylsiloxane) (30m×0.25mm×0.25μm); injection port temperature: 250°C; transmission line temperature 1: 260°C, transmission line temperature 2: 280°C; injection volume: 1μL; carrier gas: helium, 1mL / min; splitless injection; programmed temperature rise: 50°C for 1min, 20°C / min to 220°C, 5°C / min to 280°C, 10°C / min to 310°C, and hold for 10min; Mass spectrometry conditions: electron impact ion source (EI source, 70 eV); ion source temperature: 280 °C, transfer line temperature: 280 °C. Solvent delay: 4 min. Acquisition mode: full scan mode, m / z scan range 50-400, AGC: 1×e 6 , resolution: 60000.

2. The rapid screening method for non-ophthalic plasticizers in processed foods according to claim 1, characterized in that: The 36 non-phthalate plasticizers are: triethyl phosphate, diethyl maleate, 2-ethylhexyl acrylate, dimethyl adipate, diethyl adipate, diisobutyl fumarate, dimethyl terephthalate, dimethyl isophthalate, dibutyl maleate, dimethyl azelaic acid, dibutyl fumarate, dibutyl itaconate, dimethyl sebacate, tributyl phosphate, diethyl azelaic acid, dibutyl adipate, diethyl sebacate, diethylhexyl maleate, dibutyl sebacate, di(2-ethylhexyl) itaconate Ester, di(2-ethylhexyl) fumarate, di(2-ethylhexyl) adipate, triphenyl phosphate, diisooctyl diphenyl phosphate, tri(2-ethylhexyl) phosphate, di-n-octyl adipate, o-tricresyl phosphate, m-tricresyl phosphate, di(2-ethyl)hexyl isophthalate, bis(2-ethylhexyl) azelaic acid, diphenyl isophthalate, diphenyl terephthalate, di(2-ethyl)hexyl terephthalate, tricresyl phosphate, bis(2-ethylhexyl) sebacate, di-n-octyl isophthalate.

3. The rapid screening method for non-o-phthalate plasticizers in processed foods according to claim 1 or 2, characterized in that: The processed foods are: alcoholic beverages, edible vegetable oils, infant formula milk powder and food.

4. The rapid screening method for non-o-phthalate plasticizers in processed foods according to claim 3, characterized in that: It includes the following steps: a. Sample pretreatment; b. Detection is carried out using the chromatographic conditions and mass spectrometry conditions described in claim 1.

5. The rapid screening method for non-o-phthalate plasticizers in processed foods according to claim 4, characterized in that: Sample pretreatment methods include: (1) Alcohol Accurately weigh 1.0 g of the sample into a 25 mL ground-mouth glass tube with a stopper, accurately add 10 mL of n-hexane, vortex for 5 min, ultrasonically extract for 30 min, and centrifuge at 1000 r / min for 5 min; take 2.5 mL of the supernatant into a 10 mL glass nitrogen blowpipe, blow nitrogen in a 40°C water bath until nearly dry, accurately dilute to 1.0 mL with n-hexane, vortex to mix, and provide for GC-Q / Orbitrap HRMS analysis; (2) Vegetable oil Accurately weigh 0.5g of the sample into a 25mL stoppered ground-mouth glass tube, accurately add 10mL of acetonitrile, vortex for 5min, ultrasonically extract for 30min, and centrifuge at 1000r / min for 5min. The supernatant is to be purified; take 7mL of the supernatant and add it to a 25mL stoppered ground-mouth glass tube containing 500mg Silica, 500mg PSA and 50mg C 18 Place in a 10mL glass tube, vortex mix for 5min, and centrifuge at 1000r / min for 5min. Accurately pipette 5mL of supernatant into a 10mL glass nitrogen blowpipe, blow to nearly dryness with nitrogen in a 40℃ water bath, accurately make up to 1.0mL with n-hexane, vortex mix, and prepare for GC-Q / Orbitrap HRMS analysis; (3) Milk powder samples Accurately weigh 0.5g of the sample into a 25mL stoppered ground glass tube, add 2mL of 20% NaCl solution, then accurately add 10mL of acetonitrile, vortex for 5min, ultrasonically extract for 30min, add 1g of NaCl, mix well, and centrifuge at 1000r / min for 5min. The supernatant is to be purified; take 7mL of the supernatant and add it to a 500mg silica, 500mg PSA and 50mg C 18 Place in a 10mL glass tube, vortex mix for 5min, and centrifuge at 1000r / min for 5min. Accurately pipette 5mL of supernatant into a 10mL glass nitrogen blowpipe, blow to nearly dryness with nitrogen in a 40℃ water bath, accurately dilute to 1.0mL with n-hexane, vortex mix, and prepare for GC-Q / Orbitrap HRMS analysis.

6. A high-resolution mass spectrometry screening database for non-phthalate plasticizers in processed foods, characterized by: It is high-resolution screening information of 36 non-phthalate plasticizers obtained by using the rapid screening method for non-phthalate plasticizers in processed foods described in any one of claims 1-5.

7. The high-resolution mass spectrometry screening database for non-o-phthalate plasticizers in processed foods according to claim 6, characterized in that: The high-resolution screening information of the 36 non-phthalate plasticizers is shown in the following table:

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