Determination of low-level agricultural residues in soft drinks and sports drinks by liquid chromatography/tandem mass spectrometry: single-laboratory validation.
In this study, sponsored by PepsiCo Inc., a method was validated for measurement of 11 pesticide residues in soft drinks and sports drinks. The pesticide residues determined in this validation were alachlor, atrazine, butachlor, isoproturon, malaoxon, monocrotophos, paraoxon-methyl, phorate, phorate sulfone, phorate sulfoxide, and 2,4-dichlorophenoxyacetic acid (2,4-D) when spiked at 0.100 microg/L (1.00 microg/L for phorate). Samples were filtered (if particulate matter was present), degassed (if carbonated), and analyzed using liquid chromatography with tandem mass spectrometry. Quantitation was performed with matrix-matched external standard calibration solutions. The standard curve range for this assay was 0.0750 to 10.0 microg/L. The calibration curves for all agricultural residues had coefficient of determination (r2) values greater than or equal to 0.9900 with the exception of 2 values that were 0.9285 and 0.8514. Fortification spikes at 0.100 microg/L (1.00 microg/L for phorate) over the course of 2 days (n=8 each day) for 3 matrixes (7UP, Gatorade, and Diet Pepsi) yielded average percent recoveries (and percent relative standard deviations) as follows (n=48): 94.4 (15.2) for alachlor, 98.2 (13.5) for atrazine, 83.1 (41.6) for butachlor, 89.6 (24.5) for isoproturon, 87.9 (24.4) for malaoxon, 96.1 (9.26) for monocrotophos, 101 (25.7) for paraoxon-methyl, 86.6 (20.4) for phorate, 101 (16.5) for phorate sulfone, 93.6 (25.5) for phorate sulfoxide, and 98.2 (6.02) for 2,4-D.
Paske
Nathan
N
Covance Laboratories, 3301 Kinsman Blvd., Madison, WI 53704, USA.
Berry
Bryan
B
Schmitz
John
J
Sullivan
Darryl
D
D015084:2,4-Dichlorophenoxyacetic Acid / Q000737:chemistry; D001628:Beverages; D002138:Calibration; D002623:Chemistry Techniques, Analytical / Q000379:methods*; D002853:Chromatography, Liquid / Q000379:methods*; D005504:Food Analysis; D005506:Food Contamination / Q000032:analysis*; D007753:Laboratories; D010573:Pesticide Residues / Q000032:analysis*; D010575:Pesticides / Q000737:chemistry*; D053719:Tandem Mass Spectrometry / Q000379:methods*
D010573:Pesticide Residues; D010575:Pesticides; D015084:2,4-Dichlorophenoxyacetic Acid