Determination of anthraquinone in tea by stable isotope dilution assay-gas chromatography-tandem mass spectrometry

Abstract

The aim of this study was to develop an analytical method for the accurate determination of the anthraquinone residue in tea samples (Pu'er tea, oolong tea, green tea, and black tea) by stable isotope dilution assay-gas chromatographytandem mass spectrometry (SIDA-GC-MS/MS). Samples were purified by solid-phase extraction after extraction with n-hexane:acetone (1:1, v/v). The anthraquinone residue was then detected by selected reaction monitoring (SRM) in electron ionization mode. Anthraquinone-d8 was added in the tea sample extraction process to eliminate the matrix effect. The average recoveries were in the range of 84.2-98.1% at different spiked levels (0.02, 0.04 and 0.08 mg kg −1 ), and the relative standard deviations were below 9.7%. The limits of quantification, calculated as 10 times the standard deviation, was 0.02 mg kg −1 . The developed method is simple, rapid, and accurate to quantitate the concentration of anthraquinone residues in tea samples.

Detection methods, migration patterns, and health effects of pesticide residues in tea

“…Xie et al. (2020) accurately determined anthraquinone residues in tea through stable isotope dilution analysis–GC–MS/MS with an average recovery of 84.2%–98.1%. The combination of chromatography and MS is the most widely used method for the detection of pesticide residues in tea.…”

“…Dong et al (2021) used an m-PFC column filled with a variety of purification materials to adsorb tea extracts, which combined with LC-MS/MS to detect 14 pesticides in tea with strong linearity within 5-500 μg/L, showing an average recovery of 62.3%-108.8% and the limit of quantification in the range of 3-50 μg/kg. Xie et al (2020) accurately determined anthraquinone residues in tea through stable isotope dilution analysis-GC-MS/MS with an average recovery of 84.2%-98.1%. The combination of chromatography and MS is the most widely used method for the detection of pesticide residues in tea.…”