Ion chromatographic determination of perchlorate in foods by on-line enrichment and suppressed conductivity detection.
Systemic uptake of perchlorate anion, a rocket fuel component and potential thyroid function disruptor, by leafy vegetables and other crops grown in contaminated waters is a public health concern. A column-switching anion-exchange chromatographic method with suppressed conductivity detection, described in this paper, achieved a 3-6 microg/kg method limit of quantitation in analysis of the wet weight edible portion of cantaloupe, carrots, lettuce, and spinach samples with field-incurred perchlorate. A test portion was blended with dilute nitric acid, and the extract was filtered under vacuum. A portion of the measured filtrate was acidified to pH approximately 2 by addition of cation-exchange resin, 4 mL was passed through a graphitized carbon cleanup column, and an aliquot of a collected fraction was pushed through a short precolumn for anion extraction, enrichment, and injection onto the analytical column. Statistical comparison with determination by tandem mass spectrometry-ion chromatography analysis of untreated filtrate revealed that the difference between means was not significant at the 95% confidence level (P value > or = 0.12) for crops tested. In addition, the method was applied to cooked vegetables processed as baby food.
Niemann
Richard A
RA
Center for Food Safety and Applied Nutrition, Food and Drug Administration, 5100 Paint Branch Parkway, College Park, Maryland 20740, USA. richard.neimann@fda.hhs.gov
Krynitsky
Alexander J
AJ
Nortrup
David A
DA
D002852:Chromatography, Ion Exchange / Q000379:methods*; D028463:Cucumis melo / Q000737:chemistry; D018552:Daucus carota / Q000737:chemistry; D005504:Food Analysis / Q000379:methods*; D005638:Fruit / Q000737:chemistry; D006358:Hot Temperature; D006801:Humans; D007223:Infant; D007225:Infant Food / Q000032:analysis; D018545:Lactuca / Q000737:chemistry; D010472:Perchlorates / Q000032:analysis*
D010472:Perchlorates; C494474:perchlorate