CN115901995A

CN115901995A - Detection method of perfluorinated compounds in paper packaging material

Info

Publication number: CN115901995A
Application number: CN202211362851.1A
Authority: CN
Inventors: 朱翔; 汪宣; 徐文君
Original assignee: SHANGHAI TOBACCO PACKAGE PRINTING CO Ltd; Shanghai Tobacco Group Co Ltd
Current assignee: SHANGHAI TOBACCO PACKAGE PRINTING CO Ltd; Shanghai Tobacco Group Co Ltd
Priority date: 2022-11-02
Filing date: 2022-11-02
Publication date: 2023-04-04

Abstract

The invention provides a detection method of perfluorinated compounds in a paper packaging material, which comprises the following steps: preparing a mixed standard solution, preparing an internal standard solution, preparing a standard working solution, pretreating a sample, and detecting the sample. According to the detection method of the perfluorinated compounds in the paper packaging material, provided by the invention, the detection of multiple compounds is completed by using two isotope internal standards, and high accuracy and high sensitivity are maintained, so that the detection cost is reduced, the analysis difficulty is simplified, and the possibility of popularization of the method is improved. According to the detection method of the perfluorinated compounds in the paper packaging material, the steps of extraction, concentration, redissolution and the like are improved by the used pretreatment method, high accuracy and high sensitivity are maintained, the detection efficiency is improved, the operation difficulty is reduced, the using amount of a solvent is reduced (nitrogen blowing and redissolution steps are not needed), and the method is more environment-friendly.

Description

Detection method of perfluorinated compounds in paper packaging material

Technical Field

The invention belongs to the technical field of analysis and detection, and relates to a detection method of a perfluorinated compound in a paper packaging material.

Background

Perfluoro and polyfluoro compounds (PFAS) are a class of synthetic aliphatic hydrocarbon compounds, PFSAs with perfluoro substituted carbon number of 6 or more and PFCAs with perfluoro substituted carbon number of 7 or more are long-chain PFASs, otherwise referred to as short-chain PFASs. PFASs are widely applied to the fields of chemical industry, textiles, paper, packaging, coatings and the like due to unique inertia, hydrophobic and oleophobic properties, good sliding property, dirt repellency, dispersibility, selection diversity (the number of the compounds is as much as 5000), and the like.

Although these compounds are excellent in performance, C-F of PFASs is difficult to degrade, can be stably present in nature after being discharged to the environment, and is continuously transferred and accumulated in the biological chain. Existing toxicological studies have shown that there may be some biotoxicity for both long and short chains, with the difference that the short chain PFASs require higher doses to achieve similar effects to the long chain PFASs.

The research on the perfluorinated compounds in China is slow, and the control of the compounds is guaranteed due to the lack of abundant detection means, so that some production units can use the compounds in products intentionally and unintentionally, but are unknown. At present, the research on perfluorinated compounds in national standards and industrial standards mainly focuses on perfluorooctanoic acid, perfluorooctane sulfonic acid and salts thereof, and the research on other types of perfluorinated carboxylic acids and perfluorinated sulfonic acids in the field of paper packaging materials is much less and less. In the documents, a detection method of the perfluorinated compounds mostly adopts a high performance liquid chromatography-mass spectrometry combined method, and a quantitative method mostly adopts an isotope internal standard method; the pretreatment steps comprise liquid-liquid extraction, ion pair reagent extraction and the like, then purification of the extracting solution, concentration and blow-drying by a nitrogen blowing instrument, re-dissolution, membrane filtration and finally detection on a machine. Although these methods can fill up some of the actual gaps of the detection methods, the following outstanding defects exist: (1) Quantitation was performed using isotopic internal standards, which behave the same as the analyte in the sample matrix due to their similar structure. However, isotope internal standards are not available and expensive, and in multi-substance analysis, if a large amount of isotope internal standards are introduced, the analysis cost is increased, and the analysis difficulty is increased. (2) Although the steps of purification, nitrogen-blowing concentration, redissolution and the like in the pretreatment process can reduce the influence of the sample matrix and the solvent on the detection result, the steps are complicated, the time consumption is long, the use amount of the solvent is large and the like, the loss of the analyte in the pretreatment process can be caused, and the reproducibility and the accuracy of the detection result are greatly influenced.

Therefore, the invention provides a method for detecting various perfluorinated compounds in a paper packaging material, which not only considers the accuracy of the detection result, but also can effectively reduce the detection cost and improve the detection efficiency.

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, it is an object of the present invention to provide a method for detecting a perfluoro compound in a paper packaging material. When various short-chain and long-chain perfluorinated compounds are analyzed, the detection of various compounds is finally determined to be completed by adopting two isotope internal standards through reasonably selecting the types of the isotope internal standards; by analyzing the characteristics of the paper packaging material and optimizing the pretreatment method, the pretreatment process is greatly simplified, and the accuracy of the method is ensured.

In order to achieve the above objects and other related objects, the present invention provides a method for detecting perfluorocompounds in a paper packaging material, comprising the steps of:

preparing a mixed standard solution: respectively taking a perfluorinated compound mixed standard substance, adding a solvent to a constant volume, and preparing a mixed standard solution;

preparing an internal standard solution: respectively taking internal standard mixed standard products, adding a solvent to a constant volume, and preparing an internal standard solution;

preparing a standard working solution: respectively taking the mixed standard solution in the step 1) and the internal standard solution in the step 2) with different volumes, adding a solvent for constant volume, and preparing a series of standard working solutions with different concentrations;

sample pretreatment: weighing the paper packaging material, performing solvent extraction, adding the internal standard solution obtained in the step 2), performing vortex oscillation, standing, centrifuging, taking supernate, and filtering to obtain a sample to be detected;

sample detection: and (3) carrying out qualitative detection on the sample to be detected by using a liquid chromatography-tandem mass spectrometer (LC-MS/MS), and quantitatively detecting by using an internal standard method to obtain the content of the perfluorinated compounds in the sample to be detected.

Preferably, in step 1), the standard of the mixed standard is one or more selected from the group consisting of perfluorobutyric acid PFBA, perfluorovaleric acid PFPeA, perfluorobutane sulfonic acid PFBS, perfluorohexanoic acid PFHxA, perfluoropentane sulfonic acid PFPeS, perfluoroheptanoic acid pfhp a, perfluorohexane sulfonic acid PFHxS, perfluoroheptane sulfonic acid PFHpS, perfluorooctanoic acid PFOA, perfluorooctane sulfonic acid PFOS, perfluorononanoic acid PFNA, perfluorononane sulfonic acid PFNS, perfluorodecanoic acid PFDA, perfluorodecane sulfonic acid PFDS, perfluoroundecanoic acid PFUdA, perfluorododecanoic acid PFDoA, perfluorododecyl sodium sulfonate PFDoS, perfluorotridecanoic acid PFDA, perfluorohexadecanoic acid pfxdha, perfluorooctadecanoic acid PFDA in the paper packaging material according to claim 1.

Preferably, in step 2), the internal standard mixed standard is selected from isotope-labeled perfluorodecanoic acid MPFDA, isotope-labeled perfluorooctanoic acid M ₂ One or more of PFOA.

Preferably, in the step 1), the step 2) and the step 3), the constant volume solvent is methanol.

Preferably, in the step 4), the solvent for extraction is a methanol solution containing formic acid, which is 1.0% to 2.0% (V/V) formic acid.

Preferably, in the step 4), the vortex oscillation speed is 1000r/min-3000r/min, and the time is 15min-40min.

Preferably, in the step 4), the centrifugal rotating speed is 3000r/min-6000r/min, and the time is 2min-10min.

Preferably, in step 4), the filtration is performed with a 0.22 μm or 0.45 μm organic phase filter.

Preferably, in the qualitative detection of the liquid chromatography-tandem mass spectrometer (LC-MS/MS),

the liquid chromatography conditions were:

a chromatographic column: an Agilent C18 RRHD chromatographic column with the model of 1.8 μm multiplied by 2.1mm multiplied by 100mm;

mobile phase: the mobile phase A is methanol, and the mobile phase B is 3mM-6mM ammonium acetate water solution;

gradient elution procedure: 0min,5% A:95% of B;14min,95% a:5% of B;15min,100% A:0% of B;18min,100% A:0% of B;18.1min,5% A:95% of B;25min,5% A:95% of B;

sample introduction amount: 3-6 μ L;

flow rate: 0.1mL/min-0.5mL/min;

column temperature: 25-45 ℃;

the mass spectrum conditions are as follows:

ionization mode: electrospray ion source, negative ion mode;

mass spectrum scanning mode: dynamic Multiple Reaction Monitoring (DMRM);

atomizer pressure: 25psi to 35psi;

gas temperature: 230-300 ℃;

c; gas flow rate: 5L/min-15L/min;

sheath gas (N) ₂ ) Temperature: 300-400 ℃;

c; sheath gas (N) ₂ ) Flow rate: 8L/min-15L/min;

capillary voltage: 3000V-3800V.

Preferably, in step 5), the internal standard method comprises the following steps:

a1 Respectively carrying out LC-MS/MS detection on a series of standard working solutions with different concentrations in the step 2), respectively obtaining the linear relation between the peak area ratio of each perfluorinated compound/internal standard substance and the mass concentration ratio of the perfluorinated compound/internal standard substance, drawing corresponding standard working curves, and respectively calculating the regression equation of each perfluorinated compound standard working curve;

a2 Performing LC-MS/MS detection on the sample to be detected in the step 4) to obtain the peak area ratio of each perfluorinated compound/internal standard substance in the sample to be detected, substituting the peak area ratio into the regression equation of the standard working curve of each perfluorinated compound corresponding to the step A1), and calculating the mass of each perfluorinated compound in the sample to be detected according to the known mass concentration of the added corresponding internal standard substance.

As described above, the present invention has the following advantageous effects:

1) The detection method for the perfluorinated compounds in the paper packaging material provided by the invention has the advantages of high analysis speed, good repeatability and recovery rate, capability of completing simultaneous detection of twenty kinds of short-chain and long-chain perfluorinated compounds within 18min, and suitability for rapid screening and analysis of large-batch samples.

2) According to the detection method of the perfluorinated compounds in the paper packaging material, provided by the invention, the detection of multiple compounds is completed by using two isotope internal standards, and high accuracy and high sensitivity are maintained, so that the detection cost is reduced, the analysis difficulty is simplified, and the possibility of popularization of the method is improved.

3) According to the detection method of the perfluorinated compounds in the paper packaging material, the steps of extraction, concentration, redissolution and the like are improved by the used pretreatment method, high accuracy and high sensitivity are maintained, the detection efficiency is improved, the operation difficulty is reduced, the using amount of a solvent is reduced (nitrogen blowing and redissolution steps are not needed), and the method is more environment-friendly.

Drawings

FIG. 1 shows an ion selective chromatogram of a standard working solution according to the invention.

Reference numerals:

1 PFBA

2 PFPeA

3 PFBS

4 PFHxA

5 PFPeS

6 PFHpA

7 PFHxS

8 PFOA

9 PFHpS

10 PFOS

11 PFNA

12 PFNS

13 PFDA

14 PFDS

15 PFUdA

16 PFDoA

17 PFDoS

18 PFTrDA

19 PFHxDA

20 PFODA

Detailed Description

The present invention is further illustrated below with reference to specific examples, which are intended to be illustrative only and not to limit the scope of the invention.

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention.

The reagents and the test devices used in the following examples were all those conventionally used and commercially available.

Example 1

(1) Preparing a mixed standard solution: 0.25mL of the perfluorinated compound mixed standard substance with the concentration of 2000 mu g/L is transferred into a 50mL volumetric flask by a liquid transfer gun, and the volume is determined by methanol to prepare a standard stock solution with the concentration of 10 mu g/L. Sealed and lightproof for storage at 0-4 ℃.

(2) Preparing an internal standard solution: and transferring 20 mu L of the internal standard mixed standard substance of 2000 mu g/L into a 10mL volumetric flask by using a liquid transfer gun, and fixing the volume by using methanol to prepare a standard stock solution with the concentration of 4 mu g/L. Sealed and stored in dark at the temperature of 0-4 ℃.

(3) Preparing a standard working solution: 0.1mL, 0.5mL, 1mL, 2mL, 5mL, 10mL of the standard stock solution in (1) and 100. Mu.L of the standard working solution in (2) were each diluted with methanol to prepare a series of standard working solutions having concentrations of 0.1. Mu.g/L, 0.5. Mu.g/L, 1. Mu.g/L, 2. Mu.g/L, 5. Mu.g/L, and 10. Mu.g/L. Sealed and lightproof for storage at 0-4 ℃.

The conditions of the liquid chromatogram and the mass spectrum in the liquid chromatogram tandem mass spectrum are respectively as follows:

liquid chromatography conditions:

and (3) chromatographic column: an Agilent C18 RRHD chromatographic column with the model of 1.8 μm multiplied by 2.1mm multiplied by 100mm;

mobile phase: the mobile phase A is methanol, and the mobile phase B is 5mM ammonium acetate aqueous solution;

gradient program: 0min,5% A:95% of B;14min,95% A:5% of B;15min,100% A:0% of B;18min,100% A:0% of B;18.1min,5% A:95% of B;25min,5% A:95% of B;

sample introduction amount: 5 mu L of the solution;

flow rate: 0.3mL/min;

column temperature: at 38 ℃.

Mass spectrum conditions:

ionization mode: electrospray ion source, negative ion mode;

mass spectrum scanning mode: dynamic Multiple Reaction Monitoring (DMRM);

atomizer pressure: 25psi;

gas temperature: 250 ℃;

c; gas flow rate: 10L/min;

sheath gas (N) ₂ ) Temperature: 375 ℃;

c; sheath gas (N) ₂ ) Flow rate: 12L/min;

capillary voltage: 3500V.

The monitored ion pairs and the associated voltage parameter settings are shown in table 1.

TABLE 1 triple quadrupole ion pairs and associated Voltage parameter settings

Injecting standard working solution from low concentration to high concentration, measuring with the above instrument, and measuring with each perfluorinated compound (PFBA, PFPeA, PFBS, PFHxA, PFPeS)PFHpA, PFHxS, PFHpS, PFOA, PFOS, PFNA, PFNS, PFDA, PFDS, PFUdA, PFDoA, PFDoS, PFTrDA, PFHxDA, PFODA)/the peak area ratio of the internal standard substance and the mass concentration ratio of the perfluorinated compound/the internal standard substance are in linear relation, corresponding standard working curves are drawn, and the linear range of all the substances is 0.1-10 mug/L. Regression equation and correlation coefficient (R) thereof ² ) The detection limit, the quantification limit and are shown in table 2.

TABLE 2 Perfluorochemical regression equation, correlation coefficient, detection limits and quantitation limits

Serial number	Name of substance	Equation of standard curve	R ²	Detection limit	Limit of quantification
						1	PFBA	y＝161.96x–3.748	0.9986	0.16	0.54
2	PFPeA	y＝177.41x–0.548	0.9990	0.10	0.34
						3	PFBS	y＝43.03x–0.567	0.9989	0.036	0.12
4	PFHxA	y＝179.38x+3.450	0.9993	0.094	0.31
						5	PFPeS	y＝35.78x–0.147	0.9987	0.066	0.22
6	PFHpA	y＝180.24x+3.632	0.9987	0.060	0.20
						7	PFHxS	y＝11.79x–0.057	0.9988	0.049	0.16
8	PFOA	y＝69.59x+3.158	0.9974	0.091	0.30
						9	PFHpS	y＝14.85x–0.270	0.9998	0.079	0.26
10	PFOS	y＝13.94x+0.231	0.9973	0.016	0.052
						11	PFNA	y＝59.470x+4.178	0.9948	0.095	0.34
12	PFNS	y＝11.31x+0.044	0.9989	0.023	0.075
						13	PFDA	y＝31.31x+1.727	0.9959	0.011	0.035
14	PFDS	y＝2.67x–0.039	0.9988	0.081	0.27
						15	PFUdA	y＝37.13x+1.226	0.9986	0.039	0.13
16	PFDoA	y＝51.92x+0.869	0.9999	0.14	0.46
						17	PFDoS	y＝0.89x+0.050	0.9987	0.19	0.64
18	PFTrDA	y＝36.00x+1.099	0.9912	0.087	0.29
						19	PFHxDA	y＝12.81x+0.464	0.9999	0.15	0.50
20	PFODA	y＝6.89x+0.030	0.9997	0.017	0.056

Example 2

(1) Sample pretreatment: 1.0g of paper packaging material is accurately weighed, placed in a 50mL polypropylene centrifuge tube, added with 10mL of 1.5% (V/V) formic acid-containing methanol solution and 100. Mu.L of internal standard working solution, and vortexed at 2000r/min for 30min. Standing for 5min, transferring appropriate amount of the extract into a centrifuge tube, and centrifuging at 5000r/min for 5min. 1mL of the supernatant was removed and filtered through a 0.22 μm organic phase filter, and the filtrate was examined by LC-MS/MS.

(2) Recovery in sample experiment: 1.0g of paper packaging material is accurately weighed, and the recovery rate and precision are inspected by standard addition recovery tests with the concentrations of 1.5 mug/kg, 10 mug/kg and 20 mug/kg, and the results are shown in Table 3:

TABLE 3 recovery and precision tests in samples

As can be seen from Table 3, the method of the present invention has better recovery rate and precision.

In conclusion, the detection method for the perfluorinated compounds in the paper packaging material provided by the invention has the advantages of high analysis speed, good repeatability and recovery rate and simple pretreatment operation. Therefore, the invention effectively overcomes various defects in the prior art and has high industrial utilization value.

The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which may be made by those skilled in the art without departing from the spirit and scope of the present invention as defined in the appended claims.

Claims

1. A detection method of perfluorinated compounds in paper packaging materials is characterized by comprising the following steps:

1) Preparing a mixed standard solution: respectively taking a perfluorinated compound mixed standard substance, adding a solvent to a constant volume, and preparing a mixed standard solution;

2) Preparing an internal standard solution: respectively taking internal standard mixed standard products, adding a solvent to a constant volume, and preparing an internal standard solution;

3) Preparing a standard working solution: respectively taking the mixed standard solution in the step 1) and the internal standard solution in the step 2) with different volumes, adding a solvent for constant volume, and preparing a series of standard working solutions with different concentrations;

4) Sample pretreatment: weighing a paper packaging material, performing solvent extraction, adding the internal standard solution obtained in the step 2), performing vortex oscillation, standing, centrifuging, taking supernate, and filtering to obtain a sample to be detected;

5) Sample detection: and (3) carrying out qualitative detection on the sample to be detected by a liquid chromatography-tandem mass spectrometer (LC-MS/MS), and quantitatively detecting by adopting an internal standard method to obtain the content of the perfluorinated compounds in the sample to be detected.

2. The method for detecting a perfluoro compound in a paper packaging material according to claim 1, wherein in the step 1), the perfluoro compound is selected from one or more of perfluorobutyric acid PFBA, perfluorovaleric acid PFPeA, perfluorobutanesulfonic acid PFBS, perfluorohexanoic acid PFHxA, perfluoropentanesulfonic acid PFPeS, perfluoroheptanoic acid pfhp a, perfluorohexanesulfonic acid PFHxS, perfluoroheptanesulfonic acid PFHpS, perfluorooctanoic acid PFOA, perfluorooctanesulfonic acid PFOS, perfluorononanoic acid PFNA, perfluorononanesulfonic acid PFNS, perfluorodecanoic acid PFDA, perfluorodecanesulfonic acid PFDS, perfluoroundecanoic acid PFUdA, perfluorododecanoic acid PFDoA, perfluorododecylsulfonic acid PFDoS, perfluorotridecanoic acid trda, perfluorohexadecanoic acid pfxda, perfluorooctadecanoic acid PFODA.

3. The method for detecting perfluorinated compounds in paper packaging materials as claimed in claim 1, wherein in the step 2), the internal standard mixed standard is selected from isotope-labeled perfluorodecanoic acid MPFDA and isotope-labeled perfluorooctanoic acid M ₂ One or more of PFOA.

4. The method for detecting the perfluorinated compounds in the paper packaging material of claim 1, wherein in the steps 1), 2) and 3), the constant volume solvent is methanol.

5. The method for detecting the perfluorinated compounds in the paper packaging material as claimed in claim 1, wherein in the step 4), the extracted solvent is a methanol solution containing formic acid, which is a methanol solution of 1.0% to 2.0% formic acid.

6. The method for detecting the perfluorinated compounds in the paper packaging material as claimed in claim 1, wherein in the step 4), the vortex oscillation speed is 1000r/min-3000r/min, and the time is 15min-40min.

7. The method for detecting the perfluorinated compounds in the paper packaging material as claimed in claim 1, wherein in the step 4), the centrifugal rotation speed is 3000r/min-6000r/min, and the time is 2min-10min.

8. The method for detecting perfluoro compounds in paper packaging material according to claim 1, characterized in that in step 4), the filtration is performed by using 0.22 μm or 0.45 μm organic phase filtration membrane.

9. The method for detecting the perfluorinated compounds in the paper packaging material as claimed in claim 1, wherein the qualitative detection by liquid chromatography-tandem mass spectrometry (LC-MS/MS) comprises the following technical characteristics:

b1 Conditions for liquid chromatography

A chromatographic column: a C18 chromatographic column, wherein the chromatographic column comprises a chromatographic column body,

mobile phase: the mobile phase A is methanol, and the mobile phase B is 3mM-6mM ammonium acetate aqueous solution;

gradient elution procedure: 0min,5% A:95% by weight of B;14min,95% A:5% by weight of B;15min,100% A:0% by weight of B;18min, 100. The A:0% by weight of B;18.1min,5% A:95% by weight of B;25min,5% A:95% by weight of B;

sample introduction amount: 3-6 μ L;

flow rate: 0.1mL/min-0.5mL/min;

column temperature: 25-45 ℃;

b2 Conditions of mass spectrometry

Ionization mode: electrospray ion source, negative ion mode;

mass spectrum scanning mode: dynamic Multiple Reaction Monitoring (DMRM);

atomizer pressure: 25psi to 35psi;

gas temperature: 230-300 ℃;

c; gas flow rate: 5L/min-15L/min;

sheath gas (N) ₂ ) Temperature: 300-400 ℃;

c; sheath gas (N) ₂ ) Flow rate: 8L/min-15L/min;

capillary voltage: 3000V-3800V.

10. The method for detecting perfluorinated compounds in paper packaging materials as claimed in claim 1, wherein the chromatographic column: agilent C18 RRHD chromatography column with model of 1.8 μm × 2.1mm × 100mm.