Rapid and simultaneous analysis of dichlorvos, malathion, carbaryl, and 2,4-dichlorophenoxy acetic acid in citrus fruit by flow-injection ion spray ionization tandem mass spectrometry

Abstract

A simple method for the rapid and simultaneous analysis of dichlorvos (DDVP), malathion, carbaryl, and 2,4-dichlorophenoxy acetic acid (2,4-D) in citrus fruit, which uses flow-injection ion spray ionization tandem mass spectrometry, has been developed for the first time. The method involves the combined use of stable isotopically labeled internal standards (DDVP- d 6, malathion- d 10, carbaryl- d 7, and 2,4-D- d 5) and a multiple reaction monitoring technique. The average recoveries for the pesticides at the same concentrations as their tolerance levels (DDVP: 0.1–0.2 μg g −1; malathion: 0.5–4.0 μg g −1; carbaryl: 1.0 μg g −1; 2,4-D: 1.0–2.0 μg g −1) ranged from 90 to 119% with the relative standard deviation (R.S.D.) ranging from 1.0 to 13.1% ( n = 5). Analysis time, including sample preparation and determination, was only 15 min. The present method is effective for screening DDVP, malathion, carbaryl, and 2,4-D in citrus fruit.