Determination of pesticide multi-residues in green tea using a modified QuEChERS extraction and liquid chromatography tandem mass spectrometry technique

Abstract

A modifi ed QuEChERS method was developed and validated for determination of pesticide multi-residues in green tea by liquid chromatography tandem mass spectrometry. Lead acetate was fi rst time used together with primary secondary amine and graphite carbon black to eliminate tannin, caffeine, and other pigments in tea and thus reduced the matrix effects. The method was compared to the original QuEChERS method as well as A.O.A.C. QuEChERS method. For accurate quantifi cation, the matrix matched calibration technique was used. The method showed good performance in the concentration range from 0.01 to 1 mg kg -1. All pesticides could be quantifi ed at and lower than 0.01 mg kg -1 . Recoveries were from 70 to 120% and repeatabilities were <15% RSD depending on the compounds.

Laboratory validation of an LC-MS/MS method for simultaneous determination of carbamate residues in vegetables

“…1-2). These results were in agreement with the retention time and product ions reported by other studies (Ahn et al, 2021;Tran et al, 2015;Ma et al, 2020). As shown in Figure 2, our results also showed good symmetric peaks, indicating that the MS/MS could give high selectivity and sensitivity for the detection of pesticides in vegetable samples.…”

“…Another study by Tran et al (2015) used a mobile phase composed of 0.1% (v/v) acetic acid in water (eluent A) and MeOH (eluent B) (Tran et al, 2015). However, the result showed the peak of methomyl was not symmetric due to strong interaction with the residual silanol group on the packing surface of the LC column.…”

“…The extraction procedure of carbamate pesticides from vegetables plays an essential part in analytical methods. To extract pesticides from samples, some researchers have applied one of two versions of the public QuEChERS method, including the original version by Anastassiades et al (2005) 2015) used a modified QuEChERS method, using lead acetate in the extraction step to absorb polyphenols, caffeine, and pigments in green tea (Tran et al, 2015). The study showed that the use of lead acetate was important to obtain a better cleaning and a higher recovery because green tea is rich in polyphenols and caffeine.…”

Monitoring pesticide residues in dates marketed in Al‐Qassim, Saudi Arabia using a QuEChERS methodology and liquid chromatography–tandem mass spectrometry

“…The QuEChERS method is based on separating compounds with different solubilities in two immiscible liquids using a single step with solvent extraction and salting‐out liquid–liquid partitioning of the water in the sample using dehydrating salts, and this was followed by a dispersive solid‐phase extraction clean‐up if needed (Majors, ; Tran, Le, & Thai‐Nguyen, ). The method is used for commodities with water content >80% (Anastassiades et al, ).…”

A Review: Sample Preparation Methods for the Pesticide Residue Analysis in Food Samples

“…A modified QuEChERS method was developed and validated for determination of pesticide multi-residues in green tea by LC-MS [26]. Lead acetate was first time used together with PSA and GCB to eliminate tannin, caffeine and other pigments in tea and thus reduced the matrix effects.…”