A Gas-Chromatographic Method for Separating and Measuring Barbiturates and Glutethimide in Blood

1971 ◽  
Vol 17 (10) ◽  
pp. 1024-1027 ◽  
Author(s):  
Ermalinda A Fiereck ◽  
Norbert W Tietz
Keyword(s):  
Quantitative Determination ◽  
Distribution Coefficient ◽  
Chromatographic Method ◽  
Internal Standard ◽  
Free Sample ◽  
The Individual ◽  
Gas Chromatographic Method ◽  
Drug Free

Abstract A gas-chromatographic method is described for the quantitative determination of 11 barbiturates and glutethimide in blood. The extracted barbiturates are methylated and injected into a 7% DC-200 column. Use of methohexital as the internal standard, as well as the addition of standards to a drug-free sample of blood, compensates for losses and for differences in the distribution coefficient of the individual barbiturates, and makes the procedure highly precise and accurate.

Qualitative and Quantitative Determination of Methaqualone in Serum by Gas Chromatography

1974 ◽  
Vol 20 (2) ◽  
pp. 249-254 ◽  
Author(s):  
M A Evenson ◽  
G L Lensmeyer
Keyword(s):  
Gas Chromatography ◽  
Quantitative Determination ◽  
Chromatographic Method ◽  
Internal Standard ◽  
Serum Concentrations ◽  
Single Extraction ◽  
Qualitative And Quantitative ◽  
Gas Chromatographic Method ◽  
Isothermal Gas

Abstract A rapid, simple, accurate, and precise isothermal gas-chromatographic method is introduced for determination of methaqualone (2-methyl-3-o-tolyl-4(3H)-quinazolinone) in serum. A single extraction of 2 ml of serum, without derivative formation, will give adequate sensitivity for quantitation of therapeutic serum concentrations of the drug within 15 min. The method is free of interferences from biological substances, as well as from commonly used drugs. A non-drug internal standard compensates for variables in extraction, injection, and instrumental changes during analysis. The coefficient of variation, day-to-day, is 5.6%. Mean recovery of added methaqualone was 80%. To compensate for the nonquantitative yield and ensure accurate results, we prepared all analytical methaqualone standards in serum.

Gas Chromatographic Determination of N-Butyl-N-ethyl-α,α,α-trifluoro-2,6-dinitro-p-toluidine and α,α,α-Trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine in Formulations

1971 ◽  
Vol 54 (3) ◽  
pp. 711-712
Author(s):  
Martha Fuzesi
Keyword(s):  
Gas Chromatography ◽  
Quantitative Determination ◽  
Electron Capture ◽  
Chromatographic Method ◽  
Chromatographic Determination ◽  
Electron Capture Detector ◽  
Reference Solution ◽  
Gas Chromatographic Method

Abstract A gas chromatographic method is described for the quantitative determination of N-butyl-N-ethyl-α,α,α-trifluoro-2,6-dinitro-p-tolindine and α,α,α-trifluoro-2,6-dinitro-N,N-dipropyI-p-toluidine herbicides in formulations. The sample is extracted with benzene, and equal amounts of sample and reference solution in the same concentration range are analyzed by gas chromatography, using an electron capture detector and an SE-30/Diatoport S column. The method has been applied successfully to laboratory-prepared and commercial samples.

Gas Chromatographic Determination of Histapyrrodine Hydrochloride in Pharmaceutical Preparations

1986 ◽  
Vol 69 (4) ◽  
pp. 612-613
Author(s):  
Ramesh T Sane ◽  
Vipul J Doshi ◽  
Sanjay K Joshi ◽  
Vijay K Shastri ◽  
Dhananjay S Sapre ◽  
...  
Keyword(s):  
Chromatographic Method ◽  
Internal Standard ◽  
Pharmaceutical Preparations ◽  
Chromatographic Determination ◽  
Chlorpheniramine Maleate ◽  
Accuracy And Precision ◽  
Label Claim ◽  
Gas Chromatographic Method

Abstract A simple gas chromatographic method is described for the determination of histapyrrodine HC1 in marketed formulations. Chlorpheniramine maleate is used as the internal standard. The amount of histapyrrodine HC1 found by the proposed method averaged 19.91 mg/tablet, compared with the label claim of 20 mg/tablet. The method was statistically evaluated for accuracy and precision.

Gas-chromatographic determination of 5-fluorocytosine in human serum.

1976 ◽  
Vol 22 (6) ◽  
pp. 772-776 ◽  
Author(s):  
S A Harding ◽  
G F Johnson ◽  
H M Solomon
Keyword(s):  
Chromatographic Method ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Mean Value ◽  
Normal Serum ◽  
Trimethylsilyl Derivative ◽  
Serum Samples ◽  
Gas Chromatographic Method

Abstract We describe a sensitive and precise gas-chromatographic method, in which cytosine is used as the internal standard, for determination of an antifungal agent, 5-fluorocytosine, in serum. The trimethylsilyl derivative of this drug is well separated from the internal standard and from normal serum constituents. Amphotericin B does not interfere with the determination of 5-fluorocytosine. The lower limit of detection for 5-fluorocytosine is 1 mg/liter when 200 mul of serum is analyzed. Within-run precision (CV), established by analysis of 10 replicates, was 4.5% at a concentration of 19.9 mg/liter. Twenty-five serum samples were analyzed for 5-fluorocytosine by a microbiological assay and by the gas-chromatographic method. Mean value observed with the bioassay was 78.5 mg/liter and with our procedure was 69.4 mg/liter. When values for our assay were regressed against values for the bioassay, slope of the least-squares line was 0.85, intercept was 2.7 mg/liter, and r was 0.93.

Gas Chromatographic Method for Determination of Diethylstilbestrol in Feeds

1969 ◽  
Vol 52 (1) ◽  
pp. 107-109 ◽  
Author(s):  
I E Smiley ◽  
E D Schall
Keyword(s):  
Chromatographic Method ◽  
Internal Standard ◽  
Commercial Feed ◽  
Gas Chromatographic Method ◽  
Feed Samples

Abstract A GLC method was developed for the determination of diethylstilbestrol in feeds within the 0.0011–0.0022% range, using dienestrol diacetate as an internal standard. A 10 g sample was extracted with 7% ethanol in chloroform and subjected to a modified alkaline cleanup. The bis-(trimethylsilyl) acetamide derivative was then prepared and determined by GLC. No interference was encountered with commercial feed samples.

Gas Chromatographic Method for Determination of Cypermethrin in Pesticide Formulations: Collaborative Study

1987 ◽  
Vol 70 (1) ◽  
pp. 51-53
Author(s):  
J F C Tyler
Keyword(s):  
Chromatographic Method ◽  
Collaborative Study ◽  
Internal Standard ◽  
Coefficients Of Variation ◽  
Pesticide Formulations ◽  
Glass Column ◽  
Technical Material ◽  
Gas Chromatographic Method ◽  
Ethylhexyl Phthalate

Abstract A gas chromatographic method for determination of total cypermethrin in technical and formulated products has been developed and subjected to a collaborative study involving IS participating laboratories. Each sample was dissolved in methyl isobutyl ketone containing di(2-ethylhexyl) phthalate as internal standard and analyzed by gas chromatography on a glass column with 3% OV-101 on Chromosorb W-HP. Each collaborator was furnished with reference stdard and 4 samples of technical material, 3 emulsifiable concentrates, one wettable powder, and one ultralow volume formulation for analysis. The coefficients of variation of the results obtained ranged from 0.955 to 1.7462%. The method has been adopted as official first action by AOAC.

scholarly journals Single-Laboratory Validation of a Gas Chromatographic Method of Direct Determination of Volatile Compounds in Spirit Drinks: Need for an Improved Interlaboratory Study

2019 ◽  
Vol 102 (2) ◽  
pp. 669-672 ◽  
Author(s):  
Siarhei V Charapitsa ◽  
Svetlana N Sytova ◽  
Anton L Korban ◽  
Lidia N Sobolenko
Keyword(s):  
Volatile Compounds ◽  
Chromatographic Method ◽  
Internal Standard ◽  
Direct Determination ◽  
Relative Bias ◽  
Interlaboratory Study ◽  
Detector Response ◽  
Gas Chromatographic Method ◽  
Single Laboratory

Abstract Background: The quality and safety control of an alcoholic drink is mainly the establishment of its chemical content, particularly the quantity of volatile compounds. Objective: A single-laboratory validation of a gas chromatographic method of direct determination of volatile compounds in spirit drinks was conducted. The discussed method applies ethanol, the major volatile component of an alcoholic beverage, as an internal standard. Possible algorithms of method validation based on interlaboratory study were proposed and described. Methods: Seven standard solutions of the following volatile compounds were prepared gravimetrically in 40% (v/v) water–ethanol solution: acetaldehyde, methyl acetate,ethyl acetate, methanol, 2-propanol, 1-propanol, isobutanol, 1-butanol, and isoamylol. Each sample wasmeasured with the proposed method 30 times in repeatability conditions. Results: Flame ionization detector response was linearly correlated with assigned concentrations at a range of 2 to5000 mg/L of absolute alcohol (AA) with coefficients of determination (R2)more than 0.995 for all analyzed components. Repeatability (RSDr ≤ 4.5%; RSDr ≤ 2.0%), reproducibility (RSDR ≤ 5.0%; RSDR ≤ 2.0%), and trueness (relative bias ≤ 2.6%; relative bias ≤ 1.4%) were obtained for low (10–25 mg/L AA for methanol and 2–10 for othervolatiles) and high (25–5000 mg/L AA for methanol and 10–5000 for other volatiles) ranges of concentrations, correspondingly. Conclusions: The method increases the reliability of measurements and eliminates manual proceduresof internal standard addition into both calibrationstandard solutions and spirit drinks.

Gas Chromatographic Determination of Dioxathion and Chlorfenvinphos in Emulsifiable Formulations and Livestock Dips

1970 ◽  
Vol 53 (3) ◽  
pp. 566-568
Author(s):  
J E Paterson
Keyword(s):  
Quantitative Determination ◽  
Chromatographic Analysis ◽  
Chromatographic Method ◽  
Silicone Oil ◽  
Chromatographic Determination ◽  
Ionization Detector ◽  
Flame Ionization ◽  
Coefficients Of Variation ◽  
Gas Chromatographic Method

Abstract A gas chromatographic method is described for the quantitative determination of dioxathion and chlorfenvinphos in emulsifiable concentrates and livestock dips. A convenient quantity of the emulsifiable formulation is dissolved in xylene and the aqueous dip is extracted with xylene for gas chromatographic analysis, using a mixed silicone oil stationary phase and a flame ionization detector. The coefficients of variation for the dioxathion and chlorfenvinphos determinations in the emulsifiable concentrate are 2.4 and 1.0%, respectively. Recoveries of the former from a fouled dip ranged from 97 to 103% and recoveries of the latter ranged from 92 to 97%.

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