An analytical method for determining 14 N-nitrosamines in an extract and its application

Abstract

The present invention discloses an analytical method for determining 14 N-nitrosamines in an extract, comprising the following steps: (1) obtaining an extract of a test object; (2) preparing an auxiliary solution for the extract; and (3) designing and analyzing UPLC-MS / MS instrument parameters. The analytical method for determining 14 N-nitrosamines in an extract provided by the present invention and its application have good content test accuracy and repeatability, can effectively reduce the number of detection times and improve detection accuracy, are suitable for promotion in the field of analysis and detection, and have broad development prospects.

Description

Technical Field

[0001] The present invention relates to the field of G01N30 / 00 of IPC classification, and in particular to an analytical method for determining 14 N-nitrosamines in an extract and an application thereof. Background Art

[0002] In the existing regulatory system for children's products, childcare products and comfort products, because these products are more likely to come into contact with the human body or even the human body, the quality of the materials used in the products is related to the quality of the overall product and has become an extremely important safety testing indicator. In order to ensure the qualification and safety of the products and the development of new products, the relevant maternal and infant products and comfort product companies have strengthened the quality testing of the above products. Among them, the detection of N-nitrosamine content in the elastomers used in the materials of the above products is one of them.

[0003] There are many types of N-nitrosamines, all of which are compounds containing N-nitroso groups. They are highly carcinogenic to the human body and cause great harm to the health of consumers. The prior art (CN201510172466.4) provides a method for analyzing the content of nitrosamines, which uses ammonium acetate extraction and other methods to simplify the extraction method, and uses UPLC-MS / MS instrument analysis to analyze the nitrosamine content in the cigarette holder. However, because the extraction and purification operations of the extract are simplified, the precision and accuracy are reduced, and the method cannot effectively analyze maternal and infant and comfort products.

[0004] Therefore, there is an urgent need for an N-nitrosamine analysis and detection method for maternal and infant and comfort products with high analytical precision, high accuracy and good operability. Summary of the invention

[0005] In order to solve the above problems, the first aspect of the present invention provides an analytical method for determining 14 N-nitrosamines in an extract, the steps comprising: (1) obtaining an extract of the object to be tested; (2) preparing an auxiliary solution for the extract; and (3) designing and analyzing UPLC-MS / MS instrument parameters.

[0006] As a preferred solution, the obtaining of the extract includes the steps of extracting the analyte with an extraction solvent and purifying and removing impurities from the extract.

[0007] As a preferred solution, the specific operation of extracting the extract of the analyte is as follows: immerse 20 to 30 analyte materials in the extraction solvent in groups, and divide them into a static group and an oscillation group, and place the samples of the static group and the oscillation group in a constant temperature oven at 60 to 80°C, keep them warm for 2 to 3 days, then take them out, cool them to room temperature, and pour the obtained extract into a PTFE sample bottle.

[0008] As a preferred solution, the specific operation of extracting the extract of the object to be tested is: immersing 24 materials to be tested in the extraction solvent in groups, and dividing them into a static group of 12 samples and an oscillation group of 12 samples, and placing the samples of the static group and the oscillation group in a constant temperature oven at 70°C, taking them out after keeping warm for 3 days, cooling them to room temperature, and pouring the obtained extract into a PTFE sample bottle.

[0009] As a preferred solution, the specific operation of purifying and removing impurities from the extract is: filtering the extract through an acrylonitrile filter membrane with a pore size of 0.05 to 0.2 microns, discarding 1.5 to 2.5 mL of the initial filtrate before filtration, and collecting 1 to 2 mL of the subsequent filtrate into a PTFE sample bottle.

[0010] As a preferred solution, the average pore size of the acrylonitrile filter membrane is 0.1 micron.

[0011] As a preferred solution, the preparation method of the acrylonitrile filter membrane comprises the following steps: (1) stirring acrylonitrile-methyl acrylate copolymer with CPL and GTA, and adding modified titanium dioxide at the same time, and stirring until uniform; (2) heating the system in the reaction container to 130-160°C, stirring vigorously under nitrogen protection, and forming a homogeneous solution; (3) pouring the homogeneous solution into a quartz plate mold, extruding it into a film, and heating it in an oven at 100°C to form it; (4) cooling the film after forming to room temperature, taking it out and soaking it in clean water for 8-12 hours, adding it to a 10wt% alkaline solution, stirring and soaking it for 3-5 hours, taking it out and washing it, and the result is obtained.

[0012] As a preferred solution, the modified titanium dioxide preparation step comprises the following steps: adding titanium dioxide to a mixed solution of deionized water, ethanol and ammonia water, then mixing tetraethyl orthosilicate with the ethanol solution, adding the tetraethyl orthosilicate solution dropwise while stirring the titanium dioxide dispersion, the reaction temperature is 50-60°C, the dropwise reaction time is 3-4 hours, and after the reaction is completed, washing and drying are performed.

[0013] In the present application, the precision and accuracy of the detection of nitrosamines in elastomers are effectively improved by preparing a modified acrylonitrile filter membrane. This is mainly because: the modified acrylonitrile filter membrane in the present application can not only form surface carboxyl hydrophilic groups under alkaline conditions to form a filtration hydration layer, but also dissolve silicon dioxide inside the membrane pores of the filter membrane, promote the removal of the titanium dioxide shell layer, form titanium dioxide assembly hanging wall in the pores, and thus form a very strong hydrophilic group channel inside the pores. In the process of extract filtration, it can effectively guide the smooth flow of the aqueous solution, thereby avoiding the formation of filter cakes and the enrichment of target compounds caused by uneven distribution of local hydration layers, thereby improving the detection accuracy.

[0014] As a preferred solution, the extraction solvent is at least one of an alkaline extraction solvent, an acidic extraction solvent, and a simulated body fluid extraction solvent.

[0015] As a preferred solution, the extraction solvent is 50-200 mmol / L ammonium acetate aqueous solution.

[0016] As a preferred solution, the auxiliary solution is the first mobile phase, the second mobile phase, the linear solution, the SST solution, the QC solution, the blank solution, the sample solution, the LOQ solution, the accuracy solution, the precision solution, and the repeatability solution.

[0017] As a preferred solution, the preparation method of the first mobile phase is: accurately pipette 500.0 μl of formic acid into a 500 mL blue-cap bottle, add 500 mL of purified water, and shake well.

[0018] As a preferred solution, the preparation method of the second mobile phase is: accurately pipette 500.0 μl of formic acid into a 500 mL blue-cap bottle, add 500 mL of methanol, and shake well.

[0019] As a preferred solution, the linear solution is a solution of different concentrations obtained by diluting 14 N-nitrosamine mother solutions with methanol.

[0020] As a preferred solution, the volume of the methanol is 10 mL.

[0021] As a preferred solution, the concentration of the 14 N-nitrosamine mother solutions in the linear solution is 1.5-25 μg / L.

[0022] As a preferred solution, the SST solution is a linear solution of 14 N-nitrosamine mother solutions with a concentration of 10 μg / L.

[0023] As a preferred solution, the QC solution is a linear solution of 14 N-nitrosamine stock solutions with a concentration of 10 μg / L.

[0024] As a preferred solution, the blank solution is methanol.

[0025] As a preferred solution, the LOQ solution is a linear solution with a concentration of 1.5 μg / L of N-nitrosamine mother solution.

[0026] As a preferred solution, the accuracy solution is divided into a low concentration level accuracy solution, a medium concentration level accuracy solution, and a high concentration level accuracy solution.

[0027] As a preferred solution, the method for preparing the accuracy solution is: transfer 14 N-nitrosamine mother solutions into a volumetric flask, dilute to volume with methanol, shake well, and prepare 3 portions in parallel using the same method.

[0028] As a preferred solution, the concentration of the 14 N-nitrosamine stock solutions in the low concentration level accuracy solution is 1.50 μg / L; the concentration of the 14 N-nitrosamine stock solutions in the medium concentration level accuracy solution is 10 μg / L; the concentration of the 14 N-nitrosamine stock solutions in the high concentration level accuracy solution is 20 μg / L.

[0029] As a preferred solution, the preparation method of the repeatability solution is: take 100.0 μl of 14 N-nitrosamine stock solutions in a 10 mL volumetric flask, dilute to volume with methanol, shake well, and prepare 6 repeatability solutions in parallel using the same method; wherein the spiked concentrations of the 14 N-nitrosamines are the same as those of the accuracy solution at the medium concentration level.

[0030] As a preferred solution, the method for preparing the precision solution is as follows: on different days, 100.0 μl of 14 N-nitrosamine mother solutions are taken into a 10 mL volumetric flask, fixed to volume with methanol, shaken well, and 6 intermediate precision solutions are prepared in parallel using the same method.

[0031] As a preferred solution, in the UPLC-MS / MS instrument parameter design and analysis process, the chromatographic column is ZORBAX Eclipse Plus C18, 1.8μm, 3*150mm; the flow rate is 0.4-0.8mL / min; the sample injection temperature is 10-20°C; the analysis time is 5-10min; the injection volume is 1-4μl; the column temperature is 40-60°C; the first mobile phase is 0.1wt% formic acid aqueous solution; and the second mobile phase is 0.1wt% formic acid methanol solution.

[0032] As a preferred solution, in the UPLC-MS / MS instrument parameter design and analysis process, the analysis gradient is, gradient type 1:

[0033] Time (min) First mobile phase (%) Second mobile phase (%) 0.00 90.00 10.00 2.00 90.00 10.00 3.00 50.00 50.00 5.00 25.00 75.00 5.10 5.00 95.00 7.00 5.00 95.00

[0034] and gradient type 2:

[0035] Time (min) Mobile phase A (%) Mobile phase B (%) 0.00 40.00 60.00 4.00 25.00 75.00 4.10 0.00 100.00 7.00 0.00 100.00

[0036] As a preferred solution, gradient type 1 is suitable for NDELA, NDMA, NMOR, NPYR, NDEA, NPIP, NDiPA, NMPhA, and NDPA among N-nitrosamine compounds.

[0037] As a preferred solution, gradient type 2 is suitable for NEPhA, NDBA, NDiBA, NDBzA, and NDiNA among N-nitrosamine compounds.

[0038] As a preferred solution, among the mass spectrometry parameters analyzed by the UPLC-MS / MS instrument, the particle source is APCI; the scanning particle mode is MRM; the spray gas is 40-50psi; the atomization temperature is 280-320°C; the evaporation chamber temperature is 330-370°C; the gas flow rate is 5-7L / min; and the capillary voltage is 1800-2200V.

[0039] As a preferred solution, the scanning parameters of the UPLC-MS / MS instrument analysis are: applicable gradient type 1:

[0040]

[0041] And apply gradient type 2:

[0042]

[0043] As a preferred solution, the object to be tested is any one of an elastomer used in children's products, an elastomer for childcare products, and an elastomer for comfort products.

[0044] The second aspect of the present invention provides an application of the above-mentioned analytical method for determining 14 N-nitrosamines in an extract, including application of the method in an analysis method for components of an elastomer material.

[0045] Beneficial effects:

[0046] 1. The present application provides an analytical method for determining 14 N-nitrosamines in an extract, which can effectively and directionally analyze the contents of 14 N-nitrosamines in elastomers, thereby effectively determining the degree of health hazard of the elastomer material to the human body during the corresponding use process, as well as the quality of maternal and child or comfort products themselves. The method is simple and easy to use, and has high detection efficiency and accuracy, avoiding repetitive detection of elastomers.

[0047] 2. The present application provides an analytical method for determining 14 N-nitrosamines in an extract. By limiting various parameters of the UPLC-MS / MS instrument, the detection efficiency and detection results of the instrument for elastomer extracts are effectively improved, and the detection accuracy can be verified simultaneously from the preparation and use of the corresponding precision liquid.

[0048] 3. The present application provides an analytical method for determining 14 N-nitrosamines in an extract, which can effectively improve the precision and accuracy of the detection of nitrosamines in elastomers by preparing a modified acrylonitrile filter membrane, so that during the filtration process of the extract, it can effectively guide the smooth flow of the aqueous solution, thereby avoiding the formation of filter cakes and the enrichment of target compounds caused by uneven distribution of local hydration layers, thereby improving the detection accuracy. DETAILED DESCRIPTION

[0049] Example 1

[0050] Example 1 The first aspect provides an analytical method for determining 14 N-nitrosamines in an extract, the steps comprising: (1) obtaining an extract of the object to be tested; (2) preparing an auxiliary solution for the extract; and (3) designing and analyzing UPLC-MS / MS instrument parameters.

[0051] The acquisition of the extract includes the steps of extracting the analyte with an extraction solvent and purifying and removing impurities from the extract.

[0052] The specific operation of extracting the extract of the test object is as follows: immerse 24 test materials in the extraction solvent in groups, and divide them into a static group of 12 samples and an oscillation group of 12 samples, and put the samples of the static group and the oscillation group into a constant temperature oven at 70°C, take them out after keeping warm for 3 days, cool them to room temperature, and pour the obtained extract into a PTFE sample bottle.

[0053] The specific operation of purifying and removing impurities from the extract is as follows: the extract is filtered through an acrylonitrile filter membrane with a pore size of 0.1 micron, 2 mL of the initial filtrate is discarded during filtration, and 1 mL of the subsequent filtrate is collected and put into a PTFE sample bottle.

[0054] The preparation method of acrylonitrile filter membrane comprises the following steps (in parts by mass): (1) stirring 2 parts of acrylonitrile-methyl acrylate copolymer with 5.5 parts of CPL and 5.5 parts of GTA, and adding 0.1 parts of modified titanium dioxide at the same time, and stirring until uniform; (2) heating the system in the reaction container to 155°C, stirring vigorously under nitrogen protection, and forming a homogeneous solution; (3) pouring the homogeneous solution into a quartz plate mold, extruding it into a film, and heating it in an oven at 100°C to form it; (4) after the film is formed, cooling it to room temperature, taking it out and soaking it in clean water for 12 hours, adding it to a 10wt% sodium hydroxide solution, stirring and soaking it for 3.5 hours, taking it out and washing it, and the result is obtained.

[0055] The preparation steps of modified titanium dioxide include the following steps (in parts by mass): adding 1 part of titanium dioxide to a mixed solution of 60 parts of deionized water, 20 parts of ethanol and 3 parts of ammonia water, then mixing 3 parts of tetraethyl orthosilicate with 60 parts of ethanol solution, adding tetraethyl orthosilicate solution dropwise while stirring the titanium dioxide dispersion, the reaction temperature is 55°C, the dropwise reaction time is 3 hours, and after the reaction is completed, washing and drying are performed.

[0056] The extraction solvent was 150 mmol / L ammonium acetate aqueous solution.

[0057] The auxiliary solutions include the first mobile phase, the second mobile phase, the linear solution, the SST solution, the QC solution, the blank solution, the sample solution, the LOQ solution, the accuracy solution, the precision solution, and the repeatability solution.

[0058] The first mobile phase was prepared by accurately transferring 500.0 μl of formic acid into a 500 mL blue-cap bottle, adding 500 mL of purified water, and shaking well.

[0059] The preparation method of the second mobile phase is as follows: accurately pipette 500.0 μl of formic acid into a 500 mL blue-cap bottle, add 500 mL of methanol, and shake well.

[0060] The linear solutions were 14 kinds of methanol solutions with N-nitrosamine stock solution concentrations of 1.5, 5, 10, 20, and 25 μg / L; and the volume of methanol was 10 mL.

[0061] The SST solution is a linear solution of 14 N-nitrosamine stock solutions with a concentration of 10 μg / L.

[0062] The QC solution was a linear solution of 14 N-nitrosamine stock solutions with a concentration of 10 μg / L.

[0063] The blank solution was methanol.

[0064] The LOQ solution is a linear solution with a concentration of 1.5 μg / L of N-nitrosamine stock solution.

[0065] The accuracy solution is divided into low concentration level accuracy solution, medium concentration level accuracy solution, and high concentration level accuracy solution.

[0066] The preparation method of the accuracy solution is as follows: transfer 14 N-nitrosamine stock solutions into a volumetric flask, dilute to 10 mL with methanol, shake well, and prepare 3 portions in parallel using the same method.

[0067] The concentration of 14 N-nitrosamine stock solutions in the low concentration level accuracy solution is 1.50 μg / L; the concentration of 14 N-nitrosamine stock solutions in the medium concentration level accuracy solution is 10 μg / L; the concentration of 14 N-nitrosamine stock solutions in the high concentration level accuracy solution is 20 μg / L.

[0068] The preparation method of the repeatability solution is as follows: take 100.0 μl of the 14 N-nitrosamine stock solutions into a 10 mL volumetric flask, dilute to volume with methanol, shake well, and prepare 6 repeatability solutions in parallel using the same method; among them, the spiked concentrations of the 14 N-nitrosamines are the same as those of the accuracy solution at the medium concentration level.

[0069] The method for preparing the precision solution is as follows: on different days, 100.0 μl of 14 N-nitrosamine mother solutions were taken into a 10 mL volumetric flask, fixed to volume with methanol, shaken well, and 6 intermediate precision solutions were prepared in parallel using the same method.

[0070] During the UPLC-MS / MS instrument parameter design and analysis process, the chromatographic column was ZORBAX Eclipse Plus C18, 1.8μm, 3*150mm; the flow rate was 0.6mL / min; the sample injection temperature was 15°C; the analysis time was 7min; the injection volume was 2μl; the column temperature was 50°C; the first mobile phase was 0.1wt% formic acid aqueous solution; and the second mobile phase was 0.1wt% formic acid methanol solution.

[0071] During the UPLC-MS / MS instrument parameter design and analysis process, the analytical gradient was, gradient type 1:

[0072] Time (min) First mobile phase (%) Second mobile phase (%) 0.00 90.00 10.00 2.00 90.00 10.00 3.00 50.00 50.00 5.00 25.00 75.00 5.10 5.00 95.00 7.00 5.00 95.00

[0073] and gradient type 2:

[0074] Time (min) Mobile phase A (%) Mobile phase B (%) 0.00 40.00 60.00 4.00 25.00 75.00 4.10 0.00 100.00 7.00 0.00 100.00

[0075] Gradient type 1 is suitable for NDELA, NDMA, NMOR, NPYR, NDEA, NPIP, NDiPA, NMPhA, NDPA among N-nitrosamine compounds.

[0076] Gradient type 2 is suitable for NEPhA, NDBA, NDiBA, NDBzA, and NDiNA among N-nitrosamine compounds.

[0077] The mass spectrometry parameters of the UPLC-MS / MS instrument analysis were as follows: the particle source was APCI; the scanning particle mode was MRM; the spray gas was 45 psi; the atomization temperature was 300°C; the evaporation chamber temperature was 350°C; the gas flow rate was 6 L / min; and the capillary voltage was 2000 V.

[0078] The object to be tested in this application is the elastomer material of a children's pacifier.

[0079] In this embodiment, the 14 N-nitrosamine mother liquors are a mixture of 13 N-nitrosamine mother liquors and N-nitrosopyrrolidine mother liquor; the 13 N-nitrosamine mother liquors are purchased from 13 N-nitrosamine mother liquors of model RS2-19-477 sold by o2si; and the N-nitrosopyrrolidine mother liquor is purchased from the N-nitrosopyrrolidine mother liquor product of model RS2-20-060 sold by Dr. Ehrenstorfer.

[0080] Performance Evaluation

[0081] Precision-Repeatability:

[0082] Injection repeatability: Take the SST solution and repeat the injection for 6 times. Calculate the RSD of the peak area of ​​the target substance for 6 injections. The RSD should not exceed 8%.

[0083] Quality Control (QC): After the linearity test is completed and no more than ten samples have been taken, inject the QC solution and calculate the total RSD (tRSD) of the peak areas of all target substances. The tRSD should not exceed 12%.

[0084] Verification requirements:

[0085] Linearity: Methanol and linear solution are sampled and analyzed, with the concentration of the target as the horizontal axis and the peak area of ​​the target as the vertical axis. The instrument automatically calculates the linear equation of the target, and the r of the linear equation should not be less than 0.995.

[0086] Specificity: Take a portion of the reagent blank solution, sample solution and LOQ spiked solution for analysis. There should be no obvious interference at the peak position of the reference substance. If there is an interference peak nearby, the separation between it and the target peak should be no less than 1.5. The detection value of the target in the reagent blank solution should not exceed 1 / 3 of the concentration of the LOQ solution.

[0087] LOQ: Take LOQ solution and LOQ spiked solution for analysis respectively, calculate the signal-to-noise ratio (S / N) of the target in the LOQ solution and the recovery of the target in the LOQ spiked solution. The S / N of the target in the LOQ solution should not be less than 10, the recovery of the LOQ spiked solution should be between 70% and 125%, and the RSD of the recovery should not exceed 15%.

[0088] Accuracy: Take sample solution and accuracy solution for analysis, calculate the recovery rate of the target substance in the accuracy solution, the recovery rate should be between 70% and 125%, and the RSD of the recovery rate of the same level of accuracy solution should not exceed 15%.

[0089] Precision-Repeatability: The RSD of the target substance measured in 6 replicate solutions should not exceed 15%.

[0090] Durability: Change the instrument conditions: change the flow rate from 0.60ml / min to 0.66ml / min, take the linear 3 solution and repeat the injection 6 times. The RSD of the peak area of ​​the target substance 6 times should meet the injection repeatability requirements.

[0091] Solution stability: Take the durable solution for sampling and analysis. The RSD of the measured values ​​of 6 durable solutions and 6 repeatable solutions for the target substance should not exceed 22%.

[0092] Precision - Intermediate Precision: The RSD of the target substance measured in 6 repeatability solutions and 6 intermediate precision solutions should not exceed 22%.

[0093] Table 1 Injection repeatability results-1

[0094]

[0095] Table 2 Injection repeatability results-2

[0096]

[0097] Table 3 Injection repeatability results-3

[0098]

[0099] Table 4 Quality Control Results-1

[0100] name NAE NDBA NDiBA NbZ NDiNA QC-1 76499 524246 188050 488573 189672 tRSD(%) 2 1 1 1 1 QC-2 76985 520185 189606 482463 186689 tRSD(%) 2 1 1 1 1 QC-3 78684 521580 188373 479321 186096 tRSD(%) 2 1 1 1 1 QC-4 78056 518246 186501 477645 184564 tRSD(%) 2 1 1 1 1

[0101] Table 5 Quality Control Results-2

[0102] name NDELA NDMA NMOR NPYR NDEA QC-1 41911 14128 23415 59034 46640 tRSD(%) 1 2 2 7 2 QC-2 40843 13620 22535 58520 46248 tRSD(%) 1 2 2 7 1 QC-3 39806 13551 23199 58252 44971 tRSD(%) 2 2 2 6 2 QC-4 40271 13320 22773 58303 45445 tRSD(%) 2 2 2 6 1

[0103] Table 5 Quality Control Results-3

[0104] name NPIP NDiPA NMh NDPA QC-1 86310 192310 16606 204069 tRSD(%) 1 1 3 1 QC-2 82434 188817 15118 202546 tRSD(%) 2 1 3 1 QC-3 90556 191242 15269 201754 tRSD(%) 3 1 3 1 QC-4 85767 191018 15357 201917 tRSD(%) 2 1 3 1

[0105] Table 6 Linearity results

[0106]

[0107] Table 7 Sample solution results

[0108] name RB (μg / L) Sample solution (μg / L) Report results (μg / kg) NDELA 0.00 0.00 <1.50 NDMA 0.00 0.00 <1.50 NMOR 0.00 0.00 <1.50 NPYR 0.00 0.00 <1.50 NDEA 0.00 0.00 <1.50 NPIP 0.00 0.00 <1.50 NDiPA 0.00 0.00 <1.50 NMh 0.00 0.00 <1.50 NDPA 0.00 0.00 <1.50 NAE 0.00 0.00 <1.50 NDBA 0.00 0.00 <1.50 NDiBA 0.00 0.00 <1.50 NbZ 0.00 0.00 <1.50 NDiNA 0.00 0.00 <1.50

[0109] Table 8 Sample solution results

[0110] name RB (μg / L) Sample solution (μg / L) Report results (μg / kg) NDELA 0.00 0.00 <1.50 NDMA 0.00 0.00 <1.50 NMOR 0.00 0.00 <1.50 NPYR 0.00 0.00 <1.50 NDEA 0.00 0.00 <1.50 NPIP 0.00 0.00 <1.50 NDiPA 0.00 0.00 <1.50 NMh 0.00 0.00 <1.50 NDPA 0.00 0.00 <1.50 NAE 0.00 0.00 <1.50 NDBA 0.00 0.00 <1.50 NDiBA 0.00 0.00 <1.50 NbZ 0.00 0.00 <1.50 NDiNA 0.00 0.00 <1.50

[0111] Table 9 LOQ test S / N results

[0112]

[0113] Table 10 Accuracy solution original results

[0114]

[0115] Table 11 Recovery of low concentration level accuracy solution

[0116]

[0117] Table 12 Recovery of concentration level accuracy solutions

[0118]

[0119] Table 13 Recovery of high concentration level accuracy solution

[0120]

[0121] Table 14 Repeatability test results

[0122]

[0123] Table 15 Durability test results

[0124]

[0125] Table 16 Precision-intermediate precision test results

[0126]

[0127] It can be seen from the examples and Tables 1 to 16 that the analytical method for determining 14 N-nitrosamines in an extract provided by the present invention and its application have good content test accuracy and repeatability, can effectively reduce the number of tests and improve the detection accuracy, are suitable for promotion in the field of analysis and detection, and have broad development prospects.

Claims

1. An analytical method for determining 14 N-nitrosamines in an extract, characterized in that: The steps include: (1) Obtaining the extract of the analyte; (2) Preparing the auxiliary solution of the extract; (3) Designing and analyzing the UPLC-MS / MS instrument parameters; The obtaining of the extract includes the steps of extracting the analyte with an extraction solvent and purifying and removing impurities from the extract; The specific operation of extracting the sample with the extraction solvent is as follows: immersing 20 to 30 samples of the sample in the extraction solvent, and dividing the samples into a static group and an oscillation group, and placing the samples of the static group and the oscillation group in a constant temperature oven at 60 to 80° C., taking them out after keeping them warm for 2 to 3 days, cooling them to room temperature, and pouring the obtained extract into a PTFE sample bottle; The specific operation of purifying and removing impurities from the extract is as follows: filtering the extract using an acrylonitrile filter membrane with a pore size of 0.05-0.2 microns, discarding 1.5-2.5 mL of the initial filtrate before filtration, and collecting 1-2 mL of the subsequent filtrate into a PTFE sample bottle; The preparation method of the acrylonitrile filter membrane comprises the following steps: (1) stirring acrylonitrile-methyl acrylate copolymer with CPL and GTA, adding modified titanium dioxide at the same time, and stirring until uniform; (2) heating the system in the reaction container to 130-160° C., stirring vigorously under nitrogen protection, and forming a homogeneous solution; (3) pouring the homogeneous solution into a quartz plate mold, extruding it into a membrane, and heating it in an oven at 100° C. to form it; (4) cooling the membrane to room temperature after forming, taking it out and soaking it in clean water for 8-12 hours, adding it to a 10wt% alkaline solution, stirring and soaking it for 3-5 hours, taking it out and washing it, and obtaining it; The modified titanium dioxide preparation step comprises the following steps: adding titanium dioxide to a mixed solution of deionized water, ethanol and ammonia water, then mixing tetraethyl orthosilicate with the ethanol solution, dripping the tetraethyl orthosilicate solution while stirring the titanium dioxide dispersion, the reaction temperature is 50-60° C., the dripping reaction time is 3-4 hours, washing after the reaction is completed, and drying to obtain the modified titanium dioxide; The auxiliary solution comprises a first mobile phase, a second mobile phase, a linear solution, an SST solution, a QC solution, a blank solution, a sample solution, a LOQ solution, an accuracy solution, a precision solution, and a repeatability solution.

2. The analytical method for determining 14 N-nitrosamines in an extract according to claim 1, wherein the extraction solvent is at least one of an alkaline extraction solvent, an acidic extraction solvent, and a simulated body fluid extraction solvent.

3. The analytical method for determining 14 N-nitrosamines in an extract according to claim 2, characterized in that: The linear solutions are solutions of different concentrations obtained by diluting 14 N-nitrosamine mother solutions with methanol.

4. The analytical method for determining 14 N-nitrosamines in an extract according to claim 3, characterized in that: The concentrations of the 14 N-nitrosamine mother solutions in the linear solution are 1.5-25 μg / L.

5. The analytical method for determining 14 N-nitrosamines in an extract according to any one of claims 1 to 4, characterized in that: The object to be tested is any one of an elastomer used in children's products, an elastomer for childcare products, and an elastomer for comfort products.

6. An application of the analytical method for determining 14 N-nitrosamines in an extract according to any one of claims 1 to 5, characterized in that: Including the application of this method in the composition analysis method of elastomer materials.

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