GB/T 40917-2021Textiles—Determination of perfluorohexane-1-sulphonic acid and its salts (English PDF)

1 Scope

This Standard specifies the method of high-performance liquid chromatography-tandem mass spectrometer (HPLC-MS/MS) to determine the content of perfluorohexane-1-sulphonic acid and its salts (PFHxS) in textiles.

This document applies to all types of textiles.

2 Normative references

The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

GB/T 6682, Water for analytical laboratory use - Specification and test methods

3 Terms and definitions

There are no terms and definitions that need to be defined in this document.

4 Principle

Use organic solvent ultrasonic to extract perfluorohexane-1-sulphonic acid and its salts in the specimen. After the extract is filtered through a membrane, use high-performance liquid chromatography-tandem mass spectrometer (HPLC- MS/MS) to determine. Quantify with the external standard method.

5 Reagents or materials

Unless otherwise stated, the reagents used are analytically-pure and water is grade one specified in GB/T 6682.

5.1 Methanol: Chromatographically pure.

5.2 Formic acid: Chromatographically pure.

5.3 PFHxS standard product: Potassium perfluorohexanesulfonate (CAS No. 3871-99-6) or perfluorohexanesulfonic acid (CAS No. 355-46-4) standard product; Content>=99.0%.

NOTE: Perfluorohexanesulfonate exists in solution as perfluorohexanesulfonic acid ion. The sample solution and standard solution are quantified with perfluorohexanesulfonate.

5.4 PFHxS standard stock solution: Accurately weigh an appropriate amount of PFHxS standard product (5.3). Use methanol (5.1) to dissolve and dilute. Prepare a standard stock solution of the desired concentration. The concentration is 1000mg/L.

NOTE: The standard stock solution is valid for 12 months when stored in the dark at 0°C~4°C.

5.5 PFHxS standard solution: Pipette an appropriate amount of PFHxS standard stock solution (5.4). Use methanol (5.1) to prepare a standard solution with a concentration of 10 mg/L.

NOTE: The validity period of the standard solution is 6 months when stored in the dark at 0°C~4°C.

5.6 PFHxS standard working solution: Pipette an appropriate amount of PFHxS standard solution (5.5). Use methanol (5.1) to prepare standard working solutions with concentrations of 1µg/L, 3µg/L, 5µg/L, 7µg/L and 10µg/L.

NOTE: Prepare the standard working solution when it is required.

5.7 0.05% formic acid solution: Take a certain volume of formic acid (5.2) to prepare an aqueous solution with a volume fraction of 0.05%.

6 Instruments and equipment

6.1 High performance liquid chromatography-tandem mass spectrometer (HPLC-MS/MS): Equipped with an electrospray ionization source (ESI).

6.2 Extractor: 50mL, polypropylene or polyethylene tube with screw cap.

6.3 Ultrasonic generator: The working frequency is 40kHz~60kHz.

6.4 Balance: The division values are 0.0001g and 0.01g respectively.

6.5 Nylon organic phase syringe filter: The pore size is 0.22µm.

7 Analysis steps