CN104849373A - Method for testing residual amount of perfluoro caprylic acid in leather based on precolumn derivatization-high performance liquid chromatography-fluorescence detector - Google Patents

Abstract

The invention provides a method for testing the residual amount of perfluoro caprylic acid (PFOA) in leather based on a precolumn derivatization-high performance liquid chromatography-fluorescence detector. The method specifically comprises the following steps: performing ultrasonic extraction on a sample, concentrating a sample extraction liquid, performing derivatization reaction on PFOA in the extract, filtering into a sample bottle by using a membrane, testing and verifying by using a high performance liquid chromatography-fluorescence detector, at the same time implementing blank experiment, and quantitatively testing target compounds of the sample liquid by using an external standard method. High performance liquid chromatography testing parameters and testing steps are reasonably selected, a fluorescence detector is selected, and the external standard method is adopted to quantify the content, so that precise testing on the residual amount of perfluoro caprylic acid (PFOA) in leather, artificial leather and products of leather and artificial leather can be achieved. The method has the characteristics of being economic and effective, high in precision, high in anti-interference property and low in detection limit.

Description

A method for the determination of perfluorooctanoic acid residues in leather based on pre-column derivatization-high performance liquid chromatography-fluorescence detector

technical field

The invention relates to the field of product detection and analysis, in particular to a detection method for determining the residual amount of perfluorooctanoic acid (PFOA) in leather by pre-column derivatization - high performance liquid chromatography-fluorescence detector.

Background technique

The molecular formula of perfluorooctanoic acid (PFOA) is CF ₃ (CF ₂ ) ₆ COOH, and it is one of the representative members of the PFCs family. Because of its excellent hydrophobic and oleophobic properties, high thermal stability, high chemical stability and high surface activity, it is widely used in leather production as a "three-proof" surface finishing agent. However, studies have shown that PFOA is widely present in organisms and in the ecological environment, and has multiple toxicities such as reproductive toxicity, genotoxicity, developmental toxicity, immune toxicity, and liver toxicity, and has become a new type of persistent organic pollutant that has attracted attention. (POPs). In 2004, the "DuPont non-stick pan incident" that attracted attention both at home and abroad was caused by PFOA. In the EU Directive, PFOA will also be listed as a restricted substance because it is suspected to have similar hazards to PFOS, and the Norwegian Pollution Control Authority has limited the use of PFOA in 2013. Therefore, the detection and analysis of PFOA content in leather and its products has important practical significance and necessity.

So far, there is no national unified standard for the detection and analysis of PFOA in leather and its products. The local standard DB33/T 479-2009 "Determination of PFOS and PFOA in Textiles and Leather - Liquid Chromatography-Tandem Mass Spectrometry" issued by Zhejiang Province can detect PFOA content in leather. PFOA detection methods that have been developed in other industries or disciplines mainly include HPLC-MS method, HPLC-MS/MS method, GC-MS method, etc. Although these methods have high detection sensitivity, they mainly rely on high-end resolution instruments, and the detection cost is high, making it difficult to popularize. It is one of the important research directions of environmental analytical chemistry to select appropriate derivatization reagents and simple pretreatment methods, and to develop analytical and detection methods that do not depend on expensive instruments, have low analysis cost, are easy to operate, and are popular.

The purpose of the present invention is to address the deficiencies and defects of the prior art, and provide a detection method capable of determining perfluorooctanoic acid (PFOA) in leather, artificial leather and their products by means of the combination of pre-column derivatization-high performance liquid chromatography-fluorescence detection technology method. The detection method provided by the present invention is realized by pre-column derivatization-high performance liquid chromatography-fluorescence detection method, and aims to solve the problems that most of the existing methods rely on high-end analysis and detection instruments, the detection cost is high, and the method is difficult to popularize and apply. The method can realize the determination of PFOA content in leather, artificial leather and their products through reasonable selection of high-performance liquid chromatography determination parameters and test steps, detection by fluorescence detector, and quantification by external standard method. Characterized by high capacity and low detection limit. So far, there are no literature and patent reports on the detection method of PFOA in leather and its products using pre-column derivatization-high performance liquid chromatography-fluorescence detector analysis and detection at home and abroad.

Contents of the invention

A detection method based on pre-column derivatization - high performance liquid chromatography-fluorescence detector for determining the residual amount of perfluorooctanoic acid in leather, characterized in that the method for determining the residual amount of perfluorooctanoic acid (PFOA) is through 3-(bromoacetyl)coumarin (3-BrAC) pre-column derivatization-high performance liquid chromatography-fluorescence detector determination, the determination method specifically includes the following steps:

(1) Cut the sample to be tested into pieces and place it in a container, add an organic solvent, then place it in an ultrasonic cleaner for ultrasonic extraction for 0.5h~1h, and filter out the filtrate; then add an organic solvent, repeat the extraction once, and shorten the ultrasonic time for 10 min to 20 min, filter again, combine the two filtrates, and obtain a concentrated extract with a rotary evaporator;

(2) Dissolve the extract in the rotary evaporator with acetonitrile, dilute to 1 mL ~ 3 mL, vortex for 3 min ~ 10 min, pipette accurately into a 10 mL test tube, add 50 μL ~ 200 μL of derivatization reagent , after capping and sealing, shake and react at 50~80°C for 2h~5h, after the derivatization reaction is completed, cool down to room temperature quickly, place in a fume hood to balance for 1 min~5 min, filter through a 0.45 μm organic filter membrane into a sample bottle , to obtain the sample solution to be tested;

(3) According to the content of PFOA derivatives in the sample solution to be tested, select a standard working solution with a similar concentration. The response values of PFOA in the standard working solution and the sample solution to be tested should be within the linear range of the instrument. Liquid chromatography-fluorescence detector is used for measurement. If there are peaks in the sample solution and the standard solution within the same retention time, it needs to be confirmed; The test sample contains PFOA;

(4) At the same time, use high performance liquid chromatography-fluorescence detector to detect blank samples according to steps (1) and (2);

(5) Draw a standard curve with the external standard method, and calculate the content of PFOA in the sample according to the following formula:

x=(CC ₀ )* f /m

In the formula: x—the content of PFOA in the sample, the unit is mg/kg;

C—the concentration of PFOA in the sample liquid obtained from the standard curve, in μg/mL;

C ₀ —the concentration of PFOA in the blank test obtained from the standard curve, the unit is μg/mL;

f—the final dilution ratio of the test solution;

m—the mass of the sample represented by the test solution, in g.

The described detection method of pre-column derivatization - high performance liquid chromatography-fluorescence detector for determining the residual amount of perfluorooctanoic acid in leather is characterized in that the ultrasonic extraction organic solvent is methanol, ethanol, acetone, ethyl acetate, trichloro One or a mixture of methane, dichloromethane, carbon tetrachloride and acetonitrile.

A kind of precolumn derivatization - high performance liquid chromatography-fluorescence detector is characterized in that described derivatization reagent is 3-(bromoacetyl) coumarin (3- BrAC).

The described detection method of pre-column derivatization - high performance liquid chromatography-fluorescence detector for determining the residual amount of perfluorooctanoic acid in leather is characterized in that the parameter conditions of the described high performance liquid chromatography-fluorescence detector are as follows:

a) Chromatographic column: C18 chromatographic column (4.6×250 mm, 5 μm);

b) Chromatographic column temperature: 20°C~40°C;

c) Fluorescence detector: excitation wavelength 306 nm, emission wavelength 420 nm;

d) Mobile phase: 60% acetonitrile and acetonitrile, the elution program is shown in Table 1;

e) Flow rate: 0.8 ~ 1.8 mL/min;

f) Injection volume: 10 μL;

Table 1 HPLC gradient elution program

time/min 60% acetonitrile/% Acetonitrile/% 0 100 0 5 100 0 20 0 100 25 100 0 27 100 0

Claims (4)

1. one kind based on column front derivation -high performance liquid chromatography-fluorescence device measures the detection method of perfluoro caprylic acid residual quantity in leather; it is characterized in that the assay method of described perfluoro caprylic acid (PFOA) residual quantity is measured by 3-(acetyl bromide) cumarin (3-BrAC) column front derivation-high performance liquid chromatography-fluorescence device, assay method specifically comprises the following steps:

(1) testing sample is shredded be placed in container, be placed in ultrasonic washing instrument ultrasonic extraction 0.5h ~ 1h after adding organic solvent again, leach filtrate; Add organic solvent again, re-extract 1 time, ultrasonic time shortens to 10 min ~ 20min, again filters, and merges twice filtrate, the extract that Rotary Evaporators must concentrate;

(2) extract revolving and steam in bottle is dissolved with acetonitrile, be settled to 1 mL ~ 3 mL, vortex oscillation 3 min ~ 10min, accurately pipette in 10mL test tube with liquid-transfering gun, add 50 μ L ~ 200 μ L derivatization reagents, after sealing, at 50 ~ 80 DEG C, 2h ~ 5h is reacted in jolting, derivatization reaction terminates to be cooled to room temperature rapidly afterwards, be placed in fuming cupboard and balance 1 min ~ 5 min, through 0.45 μm of organic membrane filtration in sample bottle, must sample measuring liquid be treated;

(3) according to the content situation treating PFOA derivative products in sample measuring liquid, the standard working solution of selected concentration comparable, standard working solution and treat PFOA in sample measuring liquid response all should instrument detect the range of linearity in, measure with high performance liquid chromatography-fluorescence device, if there is peak to occur in sample liquid in identical retention time with standard solution, then need confirmation; Chromatographic peak retention time through confirmatory analysis measured matter is consistent with standard substance, then judge in testing sample containing PFOA;

(4) detect blank sample with high performance liquid chromatography-fluorescence device by step (1), (2) simultaneously;

(5) with external standard method drawing standard curve, the content of PFOA in sample is calculated as follows:

x=(C-C ₀)* f /m

In formula: the content of PFOA in x-sample, unit is mg/kg;

The concentration of PFOA in the sample liquid of C-obtained by typical curve, unit is μ g/mL;

C ₀the concentration of PFOA in the-blank test that obtained by typical curve, unit is μ g/mL;

The final dilution ratio of f-detection liquid;

The quality of the sample representated by m-detection liquid, unit is g.

2. a kind of column front derivation according to claim 1 -high performance liquid chromatography-fluorescence device measures the detection method of perfluoro caprylic acid residual quantity in leather, it is characterized in that described ultrasonic extraction organic solvent is the potpourri of one or more in methyl alcohol, ethanol, acetone, ethyl acetate, methenyl choloride, methylene chloride, phenixin and acetonitrile.

3. a kind of column front derivation according to claim 1 -high performance liquid chromatography-fluorescence device measures the detection method of perfluoro caprylic acid residual quantity in leather, it is characterized in that described derivatization reagent is 3-(acetyl bromide) cumarin (3-BrAC).

4. a kind of column front derivation according to claim 1 -high performance liquid chromatography-fluorescence device measures the detection method of perfluoro caprylic acid residual quantity in leather, it is characterized in that Parameter Conditions when described high performance liquid chromatography-fluorescence device measures is as follows:

A) chromatographic column: C18 chromatographic column (4.6 × 250 mm, 5 μm);

B) chromatogram column temperature: 20 DEG C ~ 40 DEG C

C) fluorescence detector: excitation wavelength 306 nm, emission wavelength 420 nm;

D) mobile phase: 60 % acetonitrile and acetonitriles, elution program is as shown in table 1; ;

E) flow velocity: 0.8 ~ 1.8 mL/min

F) sample size: 10 μ L;

Table 1 Gradient Elution program

Time/min 60% acetonitrile/% Acetonitrile/% 0 100 0 5 100 0 20 0 100 25 100 0 27 100 0

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