Rapid Confirmation of Enzyme Multiplied Immunoassay Technique (EMIT®) Cocaine Positive Urine Samples by Capillary Gas-Liquid Chromatography/Nitrogen Phosphorus Detection (GLC/NPD)

1989 ◽  
Vol 34 (1) ◽  
pp. 12609J ◽  
Author(s):  
Karl Verebey ◽  
Ann DePace
Keyword(s):  
Liquid Chromatography ◽  
Urine Samples ◽  
Gas Liquid Chromatography ◽  
Immunoassay Technique ◽  
Positive Urine ◽  
Nitrogen Phosphorus

Extraction and Cleanup of Fish, Sediment, and Water for Determination of Triaryl Phosphates by Gas-Liquid Chromatography

1981 ◽  
Vol 64 (1) ◽  
pp. 79-84
Author(s):  
Derek C G Muir ◽  
Norbert P Grift ◽  
John Solomon
Keyword(s):  
Liquid Chromatography ◽  
Soxhlet Extraction ◽  
Gel Permeation Chromatography ◽  
Gas Liquid Chromatography ◽  
Fish Samples ◽  
Alumina Treatment ◽  
Diphenyl Phosphate ◽  
Nitrogen Phosphorus ◽  
Acetone Hexane

Abstract Several techniques were evaluated for extracting triphenyl phosphate (TPP), 14C-labeled TPP, cresyl diphenyl phosphate, and tricresyl phosphate isomers (o-TCP, m-TCP, and p-TCP) from fish and sediment samples. Extracts of fish samples were cleaned up by gel permeation chromatography/alumina column chromatography; sediment extracts received alumina treatment only. Compounds were determined by gas-liquid chromatography (GLC) with nitrogenphosphorus detection. Methanol/Polytron and hexane/ball mill extraction of fish samples fortified at 0.01, 0.1, and 1.0 μg/g levels gave overall recoveries of the 5 compounds of 89 and 97%, respectively. Methanol recovered more radioactivity (97%) from fish exposed to 14C-TPP in aquaria for 24 h than did hexane from fish exposed for 16 h (79%). Refluxing fortified sediment (0.05 and 0.5 μg/g) with methanol-water (9+1) gave significantly higher recoveries (88%) of the 5 triaryl phosphates than did dichloromethane-methanol (1+1) reflux or acetone-hexane (1+1) Soxhlet extraction. Recoveries of TPP and o-, m- and p-TCP from fortified river water (0.5, 5.0, and 50 μg/L) by shaking with dichloromethane ranged from 91 to 118%. Some problems were encountered with interfering GLC peaks at low (μg/g) levels in fish and sediment extracts despite the use of nitrogen-phosphorus specific detectors.

Simultaneous Determination of Lactulose and Mannitol in Urine of Burn Patients by Gas-Liquid Chromatography

1992 ◽  
Vol 38 (3) ◽  
pp. 343-345 ◽  
Author(s):  
R L Shippee ◽  
A A Johnson ◽  
W G Cioffi ◽  
J Lasko ◽  
T E LeVoyer ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Simultaneous Determination ◽  
Urine Samples ◽  
Gas Liquid Chromatography ◽  
Burn Patients ◽  
Mucosal Permeability ◽  
Severe Burns ◽  
Urine Concentrations ◽  
Enzymatic Methods

Abstract Ratios of lactulose/mannitol excretion in urine have been used to assess the extent of intestinal permeability in various disease and trauma conditions. Reported studies have used this technique to correlate altered gastrointestinal mucosal permeability to translocation of bacteria and endotoxin, leading to occult sepsis in burn patients. Enzymatic methods of analysis for urine concentrations of mannitol and lactulose were used in these studies. We have found that urine from patients with severe burns frequently contains compounds that interfere with the enzymatic methods. We describe using gas-liquid chromatography to determine mannitol and lactulose simultaneously in the urine of burn patients. To avoid the multiple peaks for the anomeric forms of the reducing sugars during precolumn trimethylsilyl derivatization, we converted the sugars to oximes before the silylation step. The method gave good recoveries of mannitol and lactulose added to burn patients' urine samples. Unlike the enzymatic methods, gas-liquid chromatography eliminates the effect of interfering compounds and allows for the simultaneous determination of both sugars in urine samples.

Simultaneous quantitation of quinidine, procainamide, and N-acetylprocainamide in serum by gas-liquid chromatography with a nitrogen-phosphorus selective detector.

1982 ◽  
Vol 28 (5) ◽  
pp. 1187-1190 ◽  
Author(s):  
K M Kessler ◽  
P Ho-Tung ◽  
B Steele ◽  
J Silver ◽  
A Pickoff ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Clinical Application ◽  
Gas Liquid Chromatography ◽  
Drug Concentrations ◽  
Selective Detector ◽  
Nitrogen Phosphorus

Abstract We describe a single-run method for quantitating quinidine, procainamide, and N-acetylprocainamide, involving gas-liquid chromatography with a nitrogen-phosphorus selective detector. Within-run precision (CV) was 3% (x = 2 mg/L, n = 20), 6.9% (x = 4 mg/L, n = 10), and 1.5% (x = 8 mg/L, n = 8) for quinidine; 7.7% (x = 4 mg/L, n = 14), 1.6% (x = 8 mg/L, n = 16), and 2.3% (x = 12 mg/L, n = 12) for procainamide; and 6.3% (x = 5 mg/L, n = 6), 3.6% (x = 10 mg/L, n = 20), and 4.0% (x = 20 mg/L, n = 10) for N-acetylprocainamide.l Between-run precision was 3.0%(x = 2 mg/L, n = 20), 7.0% (x = 4 mg/L, n = 9), and 2.8% (x = 8 mg/L, n = 9) for quinidine; 4.7% (x = 4 mg/L, n = 10). 3.3% (x = 8 mg/L, n = 20), and 1.9% (x = 12 mg/L, n = 10) for procainamide; and 9.3% (x = 5 mg/L, n = 6), 4.3% (x = 10 mg/L, n = 20), and 3.8% (x = 20 mg/L, n = 10) for N-acetylprocainamide. Tube stoppers that contain a rubber plasticizer interfere with the technique. Clinical application and correlation with drug concentrations by this technique are discussed.

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