Determination of Carbadox-Related Residues in Swine Liver by Gas Chromatography/Mass Spectrometry with Ion Trap Detection

Abstract The Ion trap detector (ITD), in combination with a capillary gas chromatograph and under chemical ionization conditions, offers sufficient sensitivity to determine carbadoxrelated residues as the methyl ester derivative of quinoxaline- 2-carboxylic acid at 3 μg/kg or higher in porcine liver. A tetradeuterated internal standard of QME effectively compensates for losses incurred during sample preparation. The method produced mean levels of 3.3 (±0.5), 5.5 (±0.8), and 10.1 (±0.9) μg/kg for liver fortified at 3, 5, and 10 μg/kg. When applied to analysis of samples containing incurred residues of 14C-carbadox at the low μg/kg level, results were comparable to those obtained by reverse isotope dilution analysis.

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Determination of Pyrantel in Swine Liver by Flame Ionization Gas Chromatography and Confirmation by Gas Chromatography /Mass Spectrometry

Journal of AOAC INTERNATIONAL ◽

10.1093/jaoac/73.6.883 ◽

1990 ◽

Vol 73 (6) ◽

pp. 883-886

Author(s):

Susan S.C Tai ◽

Nancy Cargile ◽

Charlie J Barnes ◽

Philip Kijak

Keyword(s):

Mass Spectrometry ◽

Gas Chromatography ◽

Internal Standard ◽

Gas Chromatography Mass Spectrometry ◽

Tissue Samples ◽

Flame Ionization ◽

Chromatography Mass Spectrometry ◽

Ionization Method ◽

Swine Liver

Abstract During an evaluation of the gas chromatography/mass spectrometry (GC/MS) confirmatory procedure of Lynch and Bartoluccl for pyrantel residues in swine tissues, we developed a GC flame Ionization method for quantltatlng pyrantel residues In extracts of swine liver. The method was subjected to trial principally In the laboratories of Biospherics, Inc., using control liver, fortified control liver, and Incurred liver tissue samples. Although the method does not meet all of the current Food and Drug Administration criteria, it compares favorably to the official determinative method. Portions of the same extract can be used for quantitation and for GC/MS confirmation, true recoveries appear to be slightly higher, and an internal standard Is not required. The precision of this method equals or exceeds that of the official determinative method.

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Determination of Multiresidue Pesticides in Green Tea by Using a Modified QuEChERS Extraction and Ion-Trap Gas Chromatography/Mass Spectrometry

Journal of AOAC International ◽

10.1093/jaoac/93.4.1169 ◽

2010 ◽

Vol 93 (4) ◽

pp. 1169-1179 ◽

Cited By ~ 33

Author(s):

David Steiniger ◽

Guiping Lu ◽

Jessie Butler ◽

Eric Phillips ◽

Yolanda Fintschenko

Keyword(s):

Pesticide Residues ◽

Ion Trap ◽

Internal Standard ◽

Gas Chromatography Mass Spectrometry ◽

The European Union ◽

Modified Quechers ◽

Maximum Residue Limits ◽

Dispersive Spe ◽

Multiresidue Pesticide Analysis

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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Determination of Linuron in Potatoes Using Capillary Column Gas Chromatography/Mass Spectrometry

Journal of AOAC INTERNATIONAL ◽

10.1093/jaoac/72.6.970 ◽

1989 ◽

Vol 72 (6) ◽

pp. 970-974

Author(s):

Gregory C Mattern ◽

George M Singer ◽

Judy Louis ◽

Mark Robson ◽

Joseph D Rosen

Keyword(s):

Gas Chromatography ◽

Ion Trap ◽

Limit Of Detection ◽

Internal Standard ◽

Gas Chromatography Mass Spectrometry ◽

Phenylurea Herbicides ◽

Ionization Mode ◽

Capillary Column Gas Chromatography ◽

Ppm Level

Abstract A convenient method for the determination of the JV-methyl,iVmethoxy- phenylurea herbicide (linuron) in potatoes has been developed. The herbicide is extracted from potatoes using a slightly modifled Luke multiresidue procedure. The extract is analyzed directly by gas chromatography with cold on-column injection, using an ion trap mass spectrometer in the chemical ionization mode as the detector. Quantitation is performed using p-bromonitrobenzene as the internal standard. The limit of detection is 0.1 ppm. Recoveries of linuron in potatoes averaged 112 ± 6% at the 0.5 ppm level, and 110 ± 2% at the 0.2 ppm level. No linuron residues were found in 25 potato samples that were analyzed by this method. Two other iV-methyl,iV-methoxyphenylurea herbicides, metobromuron and chlorbromuron, are also sufficiently stable to be determined by this method, but the N,Ndialkyl- phenylurea herbicides neburon, diuron, and monuron are too thermally unstable and degrade in the gas chromatograph.

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Quantitative Analysis of Morphine in Urine by Gas Chromatography-Chemical Ionization-Mass Spectrometry, with [N-C2H3]Morphine as an Internal Standard

Clinical Chemistry ◽

10.1093/clinchem/20.4.465 ◽

1974 ◽

Vol 20 (4) ◽

pp. 465-469 ◽

Cited By ~ 22

Author(s):

Pauline A Clarke ◽

Rodger L Foltz

Keyword(s):

Chemical Ionization ◽

Internal Standard ◽

Chemical Ionization Mass Spectrometry ◽

Specific Method ◽

Ionization Mass ◽

Gas Chromatograph ◽

Quadrupole Mass ◽

Selected Ion Monitoring ◽

Highly Sensitive

Abstract A highly sensitive and specific method is described for quantitative determination of morphine in urine. Used in the method is a gas chromatograph and a computerized, quadrupole mass spectrometer operated under chemical ionization conditions. Morphine concentrations as low as 5 ng/ml can be measured by selected ion monitoring, with N-trideuteromethyl morphine as the internal standard. The sensitivity and specificity of the method is illustrated by the detection and quantitation of morphine in urine after ingestion of cough medicine containing codeine.

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