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.
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
Richard A
RA
Niemann
Alexander J
AJ
Krynitsky
David A
DA
Nortrup
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