GB/T 38592-2020 in English

Standard background and scope of application

This standard establishes a detection method for the potential carcinogen 4,4'-methylenebis(2-chloroaniline) (MOCA) in textile dyeing and finishing auxiliaries, which is applicable to the quality control of various auxiliary products. As the core content of GB/T 38592-2020, the method uses gas chromatography-triple quadrupole mass spectrometry to achieve a detection limit of 10 mg/kg.

Key technical principles

MOCA in the sample is extracted by ultrasonic toluene, and after treatment with anhydrous sodium sulfate and sodium oxide, the multiple reaction monitoring mode (MRM) of GC-MS/MS is used for qualitative and quantitative analysis. The characteristic ion pairs m/z 231→195 (quantitative) and m/z 266→195 (qualitative) ensured the detection specificity.

Key Operation Steps

1. Sample pretreatment: 0.2g sample was dissolved in 5mL water, 2g anhydrous sodium sulfate and sodium oxide were added, and 10mL toluene was ultrasonically extracted for 15min
2. Centrifugal purification: 10000r/min centrifugation for 10min, 0.22μm filter membrane filtration
3. Instrumental analysis: VF-5MS chromatographic column (30m×0.25mm×0.25μm), 60-280℃ programmed temperature, MRM mode detection

Implementation points

Technology evolution analysis

Compared with the traditional HPLC method, this standard has three major advantages: 1) detection sensitivity is increased by 5 times; 2) matrix interference is eliminated through characteristic ion pairs; 3) analysis time is shortened to 14 minutes. The total ion current chromatogram and multiple reaction monitoring mass spectrum provided in Appendix A can be used as a reference for method validation.