Abstract:

A method of high performance liquid chromatography-linear ion trap/Orbitrap high resolution mass spectrometry (HPLC-LTQ/Orbitrap MS) was used to screen and confirm carcinogenic dyes in textiles. The analytes were extracted from textile samples with pyridine/water (1/1, v/v) in a water bath under controlled conditions (95 ℃, 150 r/min), and then filtered with a 0.22 μm polytetrafluoroetylene (PTFE) membrane. The eluates were separated on a CAPCELL PAK C₁₈ column (100 mm×2.0 mm, 5 μm) using gradient elution with acetonitrile/5 mmol/L ammonium acetate aqueous solution containing 0.01% formic acid (in positive mode) and acetonitrile/5 mmol/L ammonium acetate aqueous solution (in negative mode), and finally detected by HPLC-LTQ/Orbitrap MS in ESI modes. Full scan experiments were performed over the range of m/z 200-800. The screening and quantitative analysis were carried out by the accurate mass of quasi-molecular ion and the peak area in extracted chromatogram with accurate mass, respectively. The confirmatory analysis for target compounds was performed with the retention time and qualitative fragments obtained by data-dependent scan mode. Under the optimal conditions, nine carcinogenic dyes were routinely detected with mass accuracy below 5×10^-6 (5 ppm), and good linearities were provided in their respective linear ranges with correlation coefficients higher than 0.99. The limits of detection were in the range of 0.125-25 mg/kg. The average recoveries at three spiked levels were in the range of 62.13%-116.28% with the relative standard deviations (RSDs) lower than 15%. The proposed method was applied to screen and confirm the nine carcinogenic dyes in textile samples. It is convenient and reliable.

Key words: carcinogenic dyes, high performance liquid chromatography (HPLC), high-resolution mass spectrometry (HRMS), linear ion trap/Orbitrap mass spectrometer (LTQ/Orbitrap MS), textiles