Analysis of agricultural residues on tea using d-SPE sample preparation with GC-NCI-MS and UHPLC-MS/MS.
This study presents new sample preparation and analytical procedures for the quantification of pesticides on processed tea leaves. The new method includes tea extraction and dispersive solid phase extraction (d-SPE) to prepare gas chromatography (GC) and ultrahigh-performance liquid chromatography (UHPLC)-ready samples, providing a fast and cost-effective solution for time-sensitive industrial analysis to fulfill regulatory requirements. Both GC-negative chemical ionization mass spectrometry (GC-NCI-MS) and UHPLC-tandem mass spectrometry (UHPLC-MS/MS) were employed to produce highly sensitive and reproducible data. Excellent limits of detection (typically below 1 μg/kg for GC and 10 μg/kg for UHPLC), wide linearity ranges, and good recoveries (mostly >70%) were achieved on the selected pesticides. Twenty-seven tea samples purchased from local grocery stores were analyzed using the newly developed methods. Among the pesticides analyzed, endosulfan sulfate and kelthane were the most frequently detected by GC-NCI-MS and imidacloprid and acetamiprid by UHPLC-MS/MS in these teas. The samples were found to be relatively clean, with <1 mg/kg of total pesticide residues. The organic-labeled teas were significantly cleaner than nonorganic ones. The cost per gram of tea did not correlate with pesticide residue levels detected.
Zhang
Xian
X
Ingredient Quality Department, The Coca-Cola Company, 1 Coca-Cola Plaza, Atlanta, Georgia 30313, United States.
Mobley
Nicole
N
Zhang
Jiugen
J
Zheng
Xiaomin
X
Lu
Ling
L
Ragin
Oscar
O
Smith
Christopher J
CJ
D028241:Camellia sinensis / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D010573:Pesticide Residues / Q000032:analysis* / Q000302:isolation & purification; D052616:Solid Phase Extraction / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*; D013662:Tea / Q000737:chemistry*
D010573:Pesticide Residues; D013662:Tea