The use of dispersive pipet extraction (DPX) tips for the sample cleanup of apples, pears, and oranges in the analysis of formetanate HCI.

The U.S. Environmental Protection Agency Analytical Chemistry Laboratory evaluated the effectiveness of dispersive pipet extraction (DPX) tip cleanup and compared the results with the Quick, Easy, Cheap, Effective, Rugged, and Safe dispersive tube cleanup for the sample preparation of three different fruit matrixes analyzed for formetanate HCI (FHCI).

A rapid miniaturized residue analytical method for the determination of zoxamide and its two acid metabolites in ginseng roots using UPLC-MS/MS.

A miniaturized residue method was developed for the analysis of the fungicide zoxamide and its metabolites in dried ginseng root. The zoxamide metabolites, 3,5-dichloro-1,4-benzenedicarboxylic acid (DCBC) and 3,5-dichloro-4-hydroxymethylbenzoic acid (DCHB), are small acid molecules that have not been previously extracted from the ginseng matrix with common multiresidue methods. The presented extraction method effectively and rapidly recovers both the zoxamide parent compound and its acid metabolites from fortified ginseng root.

Determination of formetanate hydrochloride in fruit samples using liquid chromatography-mass selective detection or -tandem mass spectrometry.

A rapid multiresidue method that captures residues of the insecticide formetanate hydrochloride (FHCl) in selected fruits is described. The method was used to provide residue data for dietary exposure determinations of FHCl. Using an acetonitrile extraction with a dispersive cleanup based on AOAC International method 2007.

A rapid multiresidue method for determination of pesticides in fruits and vegetables by using acetonitrile extraction/partitioning and solid-phase extraction column cleanup.

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 acid-acetonitrile (1 + 99). Water was removed by liquid-liquid partitioning with magnesium sulfate and sodium acetate.

Liquid chromatographic determination of N-methyl carbamate pesticide residues at low parts-per-billion levels in eggs.

A reversed-phase liquid chromatographic (LC) method is presented for the analysis of N-methyl carbamate pesticide residues and piperonyl butoxide in eggs at levels as low as 2 microg/kg (ppb). The study was undertaken to provide data for dietary exposure estimates used in risk analysis. The method uses an acetonitrile extraction followed by liquid-liquid partitioning and normal-phase aminopropyl solid-phase extraction column cleanup.

Multiresidue method for N-methyl carbamates and metabolite pesticide residues at the parts-per-billion level in selected representative commodities of fruit and vegetable crop groups.

A reversed-phase liquid chromatographic method with both fluorescence and mass spectrometric detection is presented for the determination of 13 parent N-methyl carbamate pesticides and their metabolites, as well as piperonyl butoxide, for a total of 24 compounds in selected fruits and vegetables. The commodities chosen were of special concern to the U.S.

Modeling Drug Residue Uptake by Eggs: Evidence of a Consistent Daily Pattern of Contaminant Transfer into Developing Preovulatory Yolks.

A study was conducted to determine if the chicken ovary deposits the pesticide lindane into preovulatory egg yolks in a daily pattern similar to that previously reported for both of the antibiotics ampicillin and oxytetracycline. Our laboratory has proposed that a variety of drugs or contaminants are deposited into preovulatory yolks in a consistent manner. This possibility of a consistent pattern of drug deposition in preovulatory yolks has been used as a foundation for a model which predicts the pattern of residues contained in laid eggs.