scholarly journals Simultaneous determination of ethylene glycol and its major toxic metabolite, glycolic acid, in serum by gas chromatography

1996 ◽  
Vol 42 (2) ◽  
pp. 292-297 ◽  
Author(s):  
H H Yao ◽  
W H Porter
Keyword(s):  
Gas Chromatography ◽  
Ethylene Glycol ◽  
Simultaneous Determination ◽  
Glycolic Acid ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Toxic Metabolite ◽  
Chromatographic Procedure ◽  
Capillary Column Gas Chromatography

Abstract We developed a gas-chromatographic procedure for the simultaneous determination of ethylene glycol (EG) and its major toxic metabolite, glycolic acid (GA), suitable for clinical use in instances of EG intoxication. After serum protein precipitation with acetonitrile (containing internal standard), the supernate is treated with 2,2-dimethoxypropane (containing dimethylformamide) to remove water, and the volume is then reduced by evaporation to <100 microL of dimethylformamide (but not to dryness). After trimethylsilyl derivatization, the resulting derivatives are analyzed by capillary column gas chromatography. Only 100 microL of serum is required and the entire determination, including calibrators and controls, takes <2 h. The method gives a linear response to at least 10 g/L EG and 5 g/L GA and has a limit of detection <10 mg/L. Intraassay CV is < or = 2.8% for EG (100 and 1000 mg/L) and GA (100 and 500 mg/L); between-day CV is < or = 6.5%. The absolute recovery from serum was 91% for EG and 77-82% for GA (200 and 2000 mg/L each). Relative to calibrators prepared bovine serum albumin (70 g/L), the recovery was 99-104% for EG (100 - 5000 mg/L) and 95-105% for GA (50 - 2500 mg/L). No clinically important interference was detected for >60 exogenous or endogenous compounds and drugs.

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

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.

Simultaneous Determination of Alachlor, Metolachlor, Atrazine, and Simazine in Water and Soil by Isotope Dilution Gas Chromatography/Mass Spectrometry

1989 ◽  
Vol 72 (2) ◽  
pp. 349-354 ◽  
Author(s):  
Lee Q Huang
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Simultaneous Determination ◽  
Isotope Dilution ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Gas Chromatography Mass Spectrometry ◽  
Selected Ion Monitoring ◽  
Chromatography Mass Spectrometry

Abstract A multiresidue method was developed for the simultaneous determination of low parts per billion (ppb) concentrations of the herbicides alachlor, metolachlor, atrazine, and simazine in water and soil using isotope dilution gas chromatography/mass spectrometry (GC/MS). Known amounts of 15N,13C-alachlor and 2H5-atrazine were added to each sample as internal standards. The samples were then prepared by a solid phase extraction with no further cleanup. A high resolution GC/low resolution MS system with data acquisition in selected ion monitoring mode was used to quantitate herbicides in the extract. The limit of detection was 0.05 ppb for water and 0.5 ppb for soil. Accuracy greater than 80% and precision better than 4% was demonstrated with spiked samples.

Determination of Phytosterols in Butter Samples by Using Capillary Column Gas Chromatography

1987 ◽  
Vol 70 (5) ◽  
pp. 912-915 ◽  
Author(s):  
Randall L Smith ◽  
Darryl M Sullivan ◽  
Earl F Richter
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Retention Time ◽  
Capillary Column ◽  
Limit Of Detection ◽  
Packed Column ◽  
Gas Chromatography Mass Spectrometry ◽  
Positive Bias ◽  
Capillary Column Gas Chromatography

Abstract A positive bias in the gas chromatographic (GC) analysis of butter for β-sitosterol was discovered when attempting to confirm values by gas chromatography/mass spectrometry (GC/MS). The source of the problem was traced to an interfering material that was not effectively separated by packed column GC. Because capillary columns are known to provide superior separation, they were substituted for packed columns in the assay, and instrument parameters were modified accordingly. A compound with a similar retention time, identified by GC/MS as lanosterol, was separated from β-sitosterol by the capillary column. The capillary column technique was applied to over 300 butter samples. The results indicate that the method can accurately quantitate β-sitosterol in butter with no known interferences. The limit of detection for this method is 1 mg/100 g. Recoveries at a level of 3 mg/100 g averaged 98% with a coefficient of variation of 3.45%

Simultaneous Detection of Several Fusarium Mycotoxins in Cereals, Grains, and Foodstuffs

1981 ◽  
Vol 64 (5) ◽  
pp. 1067-1073 ◽  
Author(s):  
Hisashi Kamimura ◽  
Motohiro Nishijima ◽  
Kazuo Yasuda ◽  
Kazuo Saito ◽  
Akihiro Ibe ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Thin Layer ◽  
Simultaneous Determination ◽  
Simultaneous Detection ◽  
Fusarium Mycotoxins ◽  
Aqueous Methanol ◽  
Systematic Method ◽  
Chromatographic Procedure ◽  
Cereal Samples

Abstract A systematic method is described for the simultaneous determination of Fusarium mycotoxins (nivalenol, deoxynivalenol, fusarenon-x, diacetoxyscirpenol, neosolaniol, T-2 toxin, HT-2 toxin, butenolide, moniliformin, and zearalenone) in cereals, grains, and foodstuffs. Mycotoxins were extracted with aqueous methanol and purified by a 2-step chromatographic procedure using Amberlite XAD-4 and Florisil columns. The column eluates were concentrated and spotted on a thin layer chromatographic (TLC) plate which was then developed in CHCL3-methanol (93 + 7) and toluene-acetonemethanol (5 + 3 + 2). Each mycotoxin was quantitated by gas chromatography (GO and TLC densitometry. The minimum detectable concentrations (μg/kg) in various test materials were: nivalenol, deoxynivalenol, and fusarenon-x, 2.0; diacetoxyscirpenol, neosolaniol, T-2 toxin, and HT-2 toxin, 80; zearalenone, 10; butenolide, 30; and moniliformin, 50. Recoveries of the mycotoxins added to various cereal samples at 1.0-2.0 Mg/g were greater than 71% and averaged 85%.

Therapeutic Monitoring of Anticonvulsant Drugs: Gas-Chromatographic Simultaneous Determination of Primidone, Phenylethylmalonamide, Carbamazepine, and Diphenylhydantoin

1975 ◽  
Vol 21 (11) ◽  
pp. 1658-1662 ◽  
Author(s):  
Charles J Least ◽  
George F Johnson ◽  
Harvey M Solomon
Keyword(s):  
Simultaneous Determination ◽  
Standard Method ◽  
Chromatographic Method ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Normal Serum ◽  
Therapeutic Monitoring ◽  
The Mean ◽  
Gas Chromatographic Method

Abstract We describe a sensitive and precise gas-chromatographic method in which benzylmalonate methylester monoamide is used as the internal standard for the simultaneous determination of primidone, phenylethylmalonamide, carbamazepine, and diphenylhydantoin. The trimethylsilyl derivatives of the anticonvulsants are well separated from each other and from normal serum constituents. The lower limit of detection for each drug is 0.5 mg/liter when 1 ml of serum is analyzed. Withinrun precision (CV), established by analysis of 10 replicates, was as follows: primidone (5.4 mg/liter), 2.6%; phenylethylmalonamide (5.5 mg/liter), 1.6%; diphenylhydantoin (6.6 mg/liter), 3.8%; and carbamazepine (10.4 mg/liter), 3.2%. Fifty specimens were analyzed for primidone and 35 for diphenylhydantoin by a standard gas-chromatographic method involving on-column methylation and by the procedure we have developed. The mean value observed for primidone with the on-column alkylation procedure was 9.3 mg/liter and with our procedure was 9.6 mg/liter. When values for our assay were regressed against values for the standard method, the slope of the least-squares line was 0.936, the intercept was 1.00 mg/liter, and r was 0.939. The mean values observed for diphenylhydantoin by on-column methylation and with our procedure were both 12.6 mg/liter. When values for our assay were regressed against the standard method, the slope of the leastsquares line was 0.944, the intercept was 0.3 mg/liter, and r was 0.988

Antipyrine metabolism in man: simultaneous determination of norantipyrine and 4-hydroxyantipyrine in urine by gas chromatography

1980 ◽  
Vol 58 (1) ◽  
pp. 17-21 ◽  
Author(s):  
T. Inaba ◽  
N. E. Fischer
Keyword(s):  
Gas Chromatography ◽  
Simultaneous Determination ◽  
Chromatographic Method ◽  
Internal Standard ◽  
Antipyrine Metabolism ◽  
Drug Oxidation ◽  
Gas Chromatographic Method

A gas chromatographic method was developed to determine metabolites of antipyrine, norantipyrine (NORA), and 4-hydroxyantipyrine in urine using p-methylated NORA as internal standard. This method requires no derivatization and has ample sensitivity to determine these metabolites in urine after ingestion of antipyrine, a compound widely used as a hepatic probe of drug oxidation.

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