Addition to Determination of Parent and Substituted Polcyclic Aromatic Hydrocarbons in High-Fat Salmon Using a Modified QuEChERs Extraction, Dispersive SPE and GC–MS

Abstract The pesticide residues in exported and imported tea products must not exceed the maximum residue limits (MRLs) regulated by the import countries. Tea is a complex matrix that obfuscates the determination of pesticide residues. Many available methods for multiresidue pesticide analysis of tea are time-consuming and require many cleanup steps. The objective of this study was to develop a simple multiresidue method by using a modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction and ion-trap GC/MS/MS, which can identify, confirm, and quantify pesticides in complex matrixes. A tea product was homogenized with water, and the pesticides were extracted with acetonitrile containing 1 acetic acid. The extract was subjected to centrifugation, initial cleanup with dispersive SPE (dSPE), solvent exchange, and final cleanup with dSPE. Diethyl-d10-parathion and triphenyl phosphate were used as the internal standard and surrogate, respectively. The final extract was injected into an ITQ 700 gas chromatograph/mass spectrometer. Quantitation of individual pesticides was based on matrix-matched calibration curves with a correlation coefficient of >0.9930 for the 22 pesticides selected for the study. The recoveries of the 22 pesticides ranged from 78 to 115, except those for diazinon (130) and malathion (122), with an average RSD of 8.7. The LOD values of all of the pesticides, except for terbufos, were below the MRLs set by the European Union and Japan.

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Development and Validation of a Procedure for Determination of Sulfonamide Residues in Pasteurized Milk Using Modified QuEChERS Method and Liquid Chromatography/Tandem Mass Spectrometry

Journal of AOAC International ◽

10.5740/jaoacint.11-539 ◽

2012 ◽

Vol 95 (5) ◽

pp. 1528-1533 ◽

Cited By ~ 10

Author(s):

Swati Ramkrishna Parab ◽

Priti Nilesh Amritkar

Keyword(s):

Matrix Effects ◽

Milk Powder ◽

The European Union ◽

Quechers Method ◽

High Fat ◽

Pasteurized Milk ◽

Modified Quechers ◽

Liquid Chromatography Tandem Mass ◽

Sulfonamide Residues

Abstract An LC method for determination of 10 sulfonamides in milk using a modified Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method was developed. Unlike the standard QuEChERS method, addition of primary secondary amine was not required for the cleanup step. Sulfonamides were analyzed from the acetonitrile layer using LC/MS/MS with electrospray ionization. Sulfonamides studied included sulfanilamide, sulfadiazine, sulfathiazole, sulfamerazine, sulfamethiazole, sulfamethazine, sulfamethoxypyridazine, sulfamethoxazole, sulfadoxin, and sulfamethoxine. Three types of milk matrixes, namely, low- and high-fat liquid pasteurized milk and milk powder, were used in the study. Matrix effects of all three matrixes were studied. The LOQs for the 10 analytes for high-fat milk were 5.3–11.2 μg/L. The combined LOQ of the 10 sulfonamides was 83.15 μg/L, which is below the maximum residue limit recommended by the European Union for sulfonamides in milk.

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A Rapid Multiresidue Method for Determination of Pesticides in Fruits and Vegetables by Using Acetonitrile Extraction/Partitioning and Solid-Phase Extraction Column Cleanup

Journal of AOAC International ◽

10.1093/jaoac/91.2.422 ◽

2008 ◽

Vol 91 (2) ◽

pp. 422-438 ◽

Cited By ~ 38

Author(s):

Frank J Schenck ◽

Amy N Brown ◽

Lynda V Podhorniak ◽

Alesia Parker ◽

Michelle Reliford ◽

...

Keyword(s):

Solid Phase Extraction ◽

Fruits And Vegetables ◽

Solid Phase ◽

Extraction Column ◽

Phase Extraction ◽

Quechers Method ◽

Multiresidue Method ◽

Modified Quechers ◽

Dispersive Spe

Abstract A modification of a rapid and inexpensive multiresidue method for determination of pesticides in fruits and vegetables (QuEChERS method) is presented. Samples were extracted by shaking with acetic acidacetonitrile (1 + 99). Water was removed by liquidliquid partitioning with magnesium sulfate and sodium acetate. The extract was subjected to a single solid-phase extraction (SPE) column cleanup, which produced a cleaner extract than did the dispersive SPE cleanup used in the original QuEChERS method. Recovery data were obtained for 316 pesticide residues, at levels ranging from 20 ppb to 1.0 ppm. Data were provided by 3 different laboratories. The modified QuEChERS method resulted in a 65 reduction in solvent usage, when compared with the traditional multiresidue methods previously used in our laboratories.

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