Method for detecting assignment amount of phthalic acid ester substances in wrist strap

Abstract

The invention relates to a method for detecting the assignment amount of phthalic acid ester substances in a wrist strap, and belongs to the technical field of chemical pollutant detection. Comprising the following steps: removing an outer package of a wristband sample, drying, cutting the sample into pieces, adding n-hexane and a deuterated internal standard, carrying out ultrasonic extraction, collecting a supernatant, carrying out nitrogen blowing concentration, filtering by a filter membrane to a constant volume, and carrying out quantitative analysis by using a gas chromatograph-mass spectrometer. According to the method disclosed by the invention, an optimized pretreatment process and instrument parameters are designed for wrist straps made of different materials, the assignment amount of six phthalic acid esters can be accurately measured, and the blank problem of targeted detection of pollutants of intelligent wearable products in the prior art is solved. The method has high sensitivity, high recovery rate and good repeatability, and is suitable for human body exposure risk assessment.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical pollutant detection, and particularly to a method for detecting the storage amount of phthalate esters in wristbands. Background Art

[0002] Phthalic Acid Esters (PAEs) are a class of compounds widely used for plastic plasticization. Because they can enhance the flexibility of materials, they are widely used in consumer products. However, PAEs have endocrine disrupting properties and can enter the human body through skin contact, respiration or ingestion, leading to reproductive toxicity, liver damage and carcinogenic risks. Research shows that the metabolites of PAEs in the human body (such as phthalic acid monoesters) also have biological activities, further exacerbating health risks.

[0003] In recent years, the popularization of smart wearable devices (such as smart watches) has made wristbands accessories that come into high-frequency contact with the human body. Commercially available wristband materials are diverse, including silicone, nylon, leather, etc. PAEs may be added during their production process to improve flexibility. However, existing detection technologies mainly focus on fields such as food and textiles, and there are few reports on the research of the storage amount of PAEs in smart wristbands. Due to problems such as mismatched pretreatment steps and unoptimized instrument parameters in traditional methods, it is difficult to accurately determine trace PAEs in such complex matrices. Therefore, it is of great practical significance to develop a detection method for PAEs dedicated to wristband materials. Summary of the Invention

[0004] The present invention aims to provide a method for detecting the storage amount of phthalate esters in wristbands to solve the blank problem of pollutant detection in smart wearable products in the prior art. By optimizing the sample pretreatment process and instrument parameters, this method realizes the high-sensitivity and high-accuracy detection of six PAEs in wristbands of various materials.

[0005] To solve the above technical problems, the technical solution proposed in this application is:

[0006] The present invention provides a method for detecting the storage amount of phthalate esters in wristbands, comprising the following steps:

[0007] (1) Remove the outer packaging of the wristband sample to be tested and clean the surface, place it in a constant temperature drying oven to stand and dry, and cut it into square particles;

[0008] (2) Weigh the sample particles, add a mixed standard of n-hexane and deuterated phthalate ester (PAEs-D4), and collect the supernatant after ultrasonic extraction;

[0009] (3) Prepare a series of standard solutions of phthalate esters;

[0010] (4) The supernatant was concentrated by nitrogen blowing and then made up to volume with n-hexane. The contents of six phthalates were quantitatively analyzed based on the standard curve using gas chromatography-mass spectrometry (GC-MS).

[0011] Furthermore, the wristband sample material in step (1) includes leather, nylon, and silicone; the drying condition is a constant temperature of 37±1°C for 2 hours; and the sample particle size is 2mm×2mm.

[0012] Furthermore, in step (2), 0.5 g of sample particles were weighed, 10 mL of n-hexane and 1 μg of PAEs-D4 mixed standard were added, and ultrasonic extraction was repeated twice after 20 minutes, and the extracts were combined.

[0013] Furthermore, step (3) includes: diluting the phthalate standard solution with n-hexane to prepare a series of standard solutions of DMP, DBP, DEP, DEHP, DIBP and DNOP, respectively, wherein the concentrations of the DMP, DBP, DEP, DEHP, DIBP and DNOP standard solutions are 0.05, 0.1, 0.2, 0.5 and 1.0 mg / L.

[0014] Furthermore, in step (4), the nitrogen blowing concentration temperature is 35° C., the concentrate is transferred to another clean glass tube, filtered through a 0.22 μm organic solvent-resistant microporous membrane into a 1.5 mL brown injection bottle, and the volume is adjusted to 1 mL with n-hexane.

[0015] Furthermore, the GC-MS working conditions include:

[0016] The chromatographic column was a DB-5MS capillary column, 30 m × 0.250 mm × 0.25 μm;

[0017] The temperature program was 60 °C for 1 min, then increased to 170 °C at 35 °C / min and held for 1 min, and then increased to 310 °C at 10 °C / min and held for 15 min;

[0018] Carrier gas: helium, purity ≥99.999%, constant pressure mode;

[0019] Collision gas: nitrogen,

[0020] Inlet temperature: 280 °C, splitless injection mode;

[0021] Ion source: electron ionization source EI, ion source temperature 260℃;

[0022] Mass analyzer: quadrupole mass analyzer;

[0023] Scan mode: Selected ion monitoring (MRM) mode.

[0024] Furthermore, the sample particles are taken from the surface of the wristband that directly contacts the skin.

[0025] Furthermore, the six PAEs-D4 mixed standards include DMP-D4, DBP-D4, DEP-D4, DEHP-D4, DIBP-D4 and DNOP-D4.

[0026] Furthermore, the retention times and characteristic ions of DMP, DBP, DEP, DEHP, DIBP and DNOP are specifically as follows:

[0027] Serial number Name Retention time (min) Selected ion (m / z) Detection limit (ng / g) 1 DMP 6.273 163、92 9.3 2 DBP 7.382 149、65 7.1 3 DEP 9.847 149、65 1.3 4 DEHP 10.75 149、93 77.4 5 DIBP 15.778 149、93 113.1 6 DNOP 17.19 149、65 142.5 .

[0028] Compared with the existing technology, the method for detecting the amount of phthalates in a wristband of the present invention has achieved the following beneficial technical effects:

[0029] The method for detecting the amount of phthalates in wristbands of the present invention can effectively detect wristbands made of various materials and accurately measure the phthalate content levels in wristbands of different materials for human exposure risk assessment. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 This is the mass spectrum of phthalates detected in Example 1 of the present invention. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0033] The present invention provides a method for detecting the amount of phthalates in a wristband, comprising the following steps:

[0034] (1) Remove the outer packaging of the wristband sample to be tested and clean the surface, place it in a constant temperature drying oven to dry, and cut it into square particles;

[0035] (2) Weigh the sample particles, add n-hexane and a mixed standard of deuterated phthalic acid esters (PAEs-D4), and collect the supernatant after ultrasonic extraction.

[0036] (3) Prepare a series of standard solutions of phthalic acid esters.

[0037] (4) Concentrate the supernatant by nitrogen blowing and then make the volume constant with n-hexane. Detect it using a gas chromatography-mass spectrometry (GC-MS) instrument, and quantitatively analyze the occurrence amounts of six phthalic acid esters based on the standard curve.

[0038] The following is further introduced in combination with examples:

[0039] (I) Materials and equipment

[0040] 1. Reagents: Standard solution of phthalic acid esters: commercially available standard product (DMP, DBP, DEP, DEHP, DIBP, and DNOP: 100.0 μg / mL); n-hexane: chromatographically pure; and methanol: analytically pure.

[0041] 2. Instruments and equipment: Gas chromatography / mass spectrometry (GC / MS): Agilent 7000A triple quadrupole mass spectrometer; electronic balance; high-power numerical control ultrasonic cleaner; nitrogen blowing instrument; muffle furnace; medical scissors; constant temperature drying oven.

[0042] Example 1

[0043] (1) Remove the interference of the sample packaging

[0044] Remove the outer packaging of the commercially available brand-new wristbands. The materials include leather, nylon, and silicone. After wiping the surface clean with methanol, place all the wristband samples in a constant temperature drying oven at 37 ± 1 °C for 2 h.

[0045] (2) Sample pretreatment

[0046] Use medical scissors to cut the surface layer of the wristband in direct contact with the human skin into particles of 2 mm × 2 mm. Accurately weigh 0.5 g of the wristband sample particles, transfer them to a 10 ml glass bottle, add 10 ml of n-hexane, add 1 μg of a mixed standard of six PAEs-D4 (DMP-D4, DBP-D4, DEP-D4, DEHP-D4, DIBP-D4, DNOP-D4), mix evenly and perform ultrasonic extraction for 20 min. Repeat twice and collect the supernatant. Concentrate the supernatant by nitrogen blowing to nearly dry at 35 °C, and accurately make the volume constant to 1.0 mL with n-hexane for analysis by GC / MS.

[0047] (3) Determination of occurrence amount

[0048] The GC-MS working conditions are as follows:

[0049] Chromatographic column: DB-5MS ultra-inert capillary column, 30m×0.250mm×0.25μm;

[0050] Temperature program: from 60 °C (hold for 1.0 min), increase the temperature at 35 °C / min to 170 °C (hold for 1.0 min), and then increase the temperature at 10 °C / min to 310 °C (hold for 15.0 min);

[0051] Carrier gas: helium, purity ≥99.999%, constant pressure mode;

[0052] Collision gas: nitrogen,

[0053] Inlet temperature: 280 °C, splitless injection mode;

[0054] Ion source: electron ionization source EI, ion source temperature 260℃;

[0055] Mass analyzer: quadrupole mass analyzer;

[0056] Scan mode: Selected ion monitoring (MRM) mode

[0057] Preparation of standard working solutions: Dilute the phthalate standard solution with n-hexane to prepare a series of standard solutions of DMP, DBP, DEP, DEHP, DIBP and DNOP with concentrations of 0.05, 0.1, 0.2, 0.5 and 1.0 mg / L respectively. In order of concentration from low to high, the standard solutions were tested on the instrument. The test method of the sample extract was the same as that of the standard solution. The mass spectra of the six phthalates are shown in Figure 2. Figure 1 The retention times and characteristic ions of the six phthalates are shown in Table 1.

[0058] Table 1 Retention times and characteristic ions of six phthalates

[0059]

[0060]

[0061] When measuring the sample, if it is found that after deducting the process blank, the chromatographic peak retention time of the sample is consistent with that of the standard solution, and the mass spectrometry fragmentation behavior (mass-to-charge ratio, abundance ratio, etc. of the fragments) is also consistent with that of the standard, it can be determined that the corresponding phthalate is present in the sample.

[0062] Draw a standard curve based on the measurement results of standard solutions with different gradients. According to the amount of phthalates in the sample, select the linear range of the instrument detection. If the detection response value of the sample exceeds the linear range of the instrument detection, it can be appropriately diluted before measurement.

[0063] This standard uses the external standard method to quantitatively analyze phthalates. In the chromatogram, select appropriate quantitative ions for peak area integration.

[0064] 1. Result calculation

[0065] The migration amount of each phthalate ester in the sample is calculated according to formula (1):

[0066]

[0067] Where: E i —The amount of a certain phthalate ester i in the sample, in μg / g;

[0068] C i —The concentration of a certain phthalate ester i in the extract obtained from the calibration curve, in μg / mL;

[0069] V—extraction volume, unit: mL;

[0070] m—sample mass, unit: g.

[0071] 2. Detection limit and quantification limit

[0072] The detection method provided by the present invention, as shown in Table 1, shows that the detection limits of six phthalates (DMP, DBP, DEP, DEHP, DIBP and DNOP) are 9.3, 7.1, 1.3, 77.4, 113.1 and 142.5 ng / g, respectively.

[0073] 3. Recovery rate

[0074] Deuterated phthalate standard solutions of known concentrations were quantitatively added to the test samples for recovery analysis. The recovery rates of the six phthalates ranged from 90.58% to 109.02%.

[0075] 4. Quality Control

[0076] The absolute difference between three independent test results obtained under repeatability conditions is not greater than 20% of the arithmetic mean of the two measured values, with a confidence level of 95%.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A method for detecting the amount of phthalates in a wristband, characterized in that: It includes the following steps: (1) Remove the outer packaging of the wristband sample to be tested, clean the surface, place it in a constant temperature drying oven for static drying, and cut it into square particles; (2) Weigh the sample particles, add n-hexane and a mixed standard of deuterated phthalate esters (PAEs-D4), collect the supernatant after ultrasonic extraction; (3) Prepare a series of phthalate ester standard solutions; (4) Concentrate the supernatant by nitrogen blowing and then make up the volume with n-hexane. Detect it using a gas chromatography-mass spectrometry (GC-MS) instrument, and quantitatively analyze the storage amounts of six phthalate esters based on the standard curve.

2. The detection method according to claim 1, wherein In step (1), the materials of the wristband sample include leather, nylon, and silica gel; the drying conditions are constant temperature at 37 ± 1 °C for 2 hours; the size of the sample particles is 2 mm × 2 mm.

3. The detection method according to claim 1, characterized in that In step (2), weigh 0.5 g of sample particles, add 10 mL of n-hexane and 1 μg of PAEs-D4 mixed standard, repeat ultrasonic extraction twice for 20 minutes each time, and combine the extraction solutions.

4. The detection method according to claim 1, characterized in that, In step (3), it includes: dilute the phthalate ester standard solution with n-hexane, and prepare a series of standard solutions of DMP, DBP, DEP, DEHP, DIBP, and DNOP respectively. The concentrations of the DMP, DBP, DEP, DEHP, DIBP, and DNOP standard solutions are 0.05, 0.1, 0.2, 0.5, 1.0 mg / L.

5. The detection method according to claim 1, wherein In step (4), the temperature for nitrogen blowing concentration is 35 °C. Transfer the concentrated solution to another clean glass tube, filter it through a 0.22 μm organic solvent-resistant microporous membrane into a 1.5 mL brown injection vial, and make up the volume to 1 mL with n-hexane.

6. The detection method according to any one of claims 1-5, characterized in that, The working conditions of the GC-MS include: The chromatographic column is a DB-5MS capillary column, 30 m × 0.250 mm × 0.25 μm; The programmed temperature rise is to hold at 60 °C for 1 minute, rise to 170 °C at a rate of 35 °C / min and hold for 1 minute, then rise to 310 °C at a rate of 10 °C / min and hold for 15 minutes; Carrier gas: helium, purity ≥ 99.999%, constant pressure mode; Collision gas: nitrogen, Injection port temperature: 280 °C, using the splitless injection mode; Ion source: electron ionization source EI, ion source temperature 260 °C; Mass analyzer: quadrupole mass analyzer; Scanning mode: selective ion monitoring (MRM) mode.

7. The detection method according to claim 1, wherein The sample particles are taken from the surface layer of the wristband that directly contacts the skin.

8. The detection method according to claim 1, wherein The six PAEs-D4 mixed standards include DMP-D4, DBP-D4, DEP-D4, DEHP-D4, DIBP-D4, and DNOP-D4.

9. The detection method according to claim 4, wherein The retention times and characteristic ions of DMP, DBP, DEP, DEHP, DIBP, and DNOP are specifically: 。

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