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.

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

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-Liquid Chromatographic Determination of T-2 Toxin in Plasma

1983 ◽  
Vol 66 (4) ◽  
pp. 909-912 ◽  
Author(s):  
Steven P Swanson ◽  
Venkatachalam Ramaswamy ◽  
Val R Beasley ◽  
William B Buck ◽  
Harold H Burmeister
Keyword(s):  
Chromatographic Method ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Aqueous Sodium Hydroxide ◽  
Chromatographic Determination ◽  
Florisil Column ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract The gas-liquid chromatographic method for the determination of T-2 toxin in plasma is described. The toxin is extracted with benzene, washed with aqueous sodium hydroxide, and chromatographed on a small Florisil column; the heptafluorobutyryl derivative is prepared by reaction with heptafluorobutyrylimidazole. The T-2 HFB derivative is chromatographed onOV-1 at 230°C and measured with an electron capture detector. Iso-T-2, an isomer of T-2 toxin, is added to samples as an internal standard before extraction. Recoveries averaged 98.0 ± 5.5% at levels ranging from 50 to 1000 ng/m L. The limit of detection is 25 ng/mL.

scholarly journals Gas Chromatographic Determination of Alachlor in Microencapsulated Formulations: Mini-Collaborative Study

1987 ◽  
Vol 70 (6) ◽  
pp. 1056-1058
Author(s):  
David F Tomkins
Keyword(s):  
Coefficient Of Variation ◽  
Chromatographic Method ◽  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Chromatographic Column ◽  
Data Points ◽  
Gas Chromatographic Method ◽  
Isothermal Gas

Abstract An isothermal gas chromatographic method for measuring alachlor in Micro-Tech® (microencapsulated) formulations was tested by 5 collaborators. The samples were prepared in acetone, and alachlor was determined using a gas chromatographic column of 10% SP- 2250 on 100-120 mesh Supelcoport. Di-n-pentylphthalate was used as the internal standard. Collaborators made single determinations on 5 samples distributed as blind duplicates. The mini-collaborative study generated 47 data points. The coefficient of variation (CV„- pooled) was 1.35%, and CVx-pooled was 0.73%. The method was simple to use and did not reveal any interferences in samples tested. The method has been adopted official first action as an AOACCIPAC method.

Gas Chromatographic Determination of Fensulfothion in Formulations: Collaborative Study

1986 ◽  
Vol 69 (3) ◽  
pp. 488-490
Author(s):  
William R Betker ◽  
◽  
E W Balcer ◽  
O O Bennett ◽  
W R Coffman ◽  
...  
Keyword(s):  
Chromatographic Method ◽  
Methylene Chloride ◽  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Gas Chromatograph ◽  
Technical Product ◽  
Coefficients Of Variation ◽  
Gas Chromatographic Method

Abstract A collaborative study was conducted on a gas chromatographic method for determination of fensulfothion. Eleven laboratories analyzed 2 technical and two 6 lb/U.S. gal. spray concentrate samples. In the analysis, samples are dissolved in methylene chloride which contains 4-chlorophenyl sulfoxide as an internal standard, and solutions are injected into a gas chromatograph equipped with an OV-330 column. Withinlaboratory repeatability was 0.79% for technical product and 0.37% for the spray concentrate samples, with coefficients of variation of 0.88 and 0.58%, respectively. Among-laboratories reproducibility was 0.81% for technical product and 0.53% for the spray concentrate, with coefficients of variation of 0.91 and 0.84%, respectively. The method has been adopted official first action.

Gas Chromatographic Determination of Isofenphos in Technical and Formulated Products: Collaborative Study

1987 ◽  
Vol 70 (1) ◽  
pp. 55-57
Author(s):  
Daniel E Terry
Keyword(s):  
Thermal Conductivity ◽  
Gas Chromatography ◽  
Chromatographic Method ◽  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Flame Ionization ◽  
Coefficients Of Variation ◽  
Gas Chromatographic Method

Abstract A gas chromatographic method for the determination of isofenphos (OFTANOL®) in isofenphos technical and liquid formulations has been developed and collaboratively studied by 11 laboratories. Two technical samples and 2 liquid flowable samples were analyzed after shaking/extracting in methanol which contained diisobutyl phthalate as an internal standard. The extracts were analyzed by gas chromatography using an SP-2100 column and either flame ionization or thermal conductivity detection. Coefficients of variation were 0.57 and 1.27% for the technical and formulated products, respectively. The GC method has been adopted official first action as a AOACCTPAC method.

Determination of carbamazepine in blood or plasma by high-pressure liquid chromatography.

1976 ◽  
Vol 22 (7) ◽  
pp. 1070-1072 ◽  
Author(s):  
P M Kabra ◽  
L J Marton
Keyword(s):  
High Pressure ◽  
Chromatographic Method ◽  
Limit Of Detection ◽  
Internal Standard ◽  
High Pressure Liquid Chromatographic ◽  
Blood Constituents ◽  
Liquid Chromatographic Method ◽  
Gas Chromatographic Method ◽  
Liquid Chromatographic

Abstract We described a sensitive and precise high-pressure liquid-chromatographic method in which 5-(p-methylphenyl)-5-phenylhydantoin is used as the internal standard in determining carbamazepine in whole blood or plasma. Carbamazepine is well separated from normal blood constituents in less than 8 min, and other commonly used anticonvulsants do not interfere with the analysis. The sensitivity of this method is adequate to quantitate 0.25 mg of carbamazepine per liter in 2 ml of sample, and the lower limit of detection is 100 ng. Twenty specimens were analyzed by a gas-chromatographic method and by the present method; the resulting correlation coefficient was greater than .980.

Gas Chromatographic Determination of Ethyl O,O-Dimethyldithiophosphoryl- 1-Phenyl Acetate in Technical Grade Cidial and Its 50% Liquid Formulation

1969 ◽  
Vol 52 (1) ◽  
pp. 52-55
Author(s):  
B Bazzi ◽  
L Abbruzzese ◽  
G Galluzzi
Keyword(s):  
Thermal Conductivity ◽  
Chromatographic Method ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Phenyl Acetate ◽  
Thermal Conductivity Detector ◽  
Liquid Formulation ◽  
Technical Grade ◽  
Gas Chromatographic Method

Abstract A gas chromatographic method has heen developed for analysis of ethyl O,O-dimethyldithiophosphoryl- 1-phenyl acetate. The insecticide or a convenient amount of an insecticidal preparation is dissolved in toluene, together with a suitable internal standard, and analyzed by gas chromatography, using a thermal conductivity detector. The precision (P = 0.05) of the method is ±1.5% of the concentration found.

Gas Chromatographic Determination of Micro Amounts of Cyanide Residues in Wines, Distilled Liquors, and Other Alcoholic Beverages

1976 ◽  
Vol 59 (6) ◽  
pp. 1390-1395 ◽  
Author(s):  
Brian L Bates ◽  
Donald R Buick
Keyword(s):  
Cyanogen Bromide ◽  
Chromatographic Method ◽  
Limit Of Detection ◽  
Chromatographic Determination ◽  
Alcoholic Beverages ◽  
Relative Standard ◽  
Standard Deviations ◽  
Absorber Solution ◽  
Gas Chromatographic Method

Abstract A gas chromatographic method for the determination of cyanide residues in alcoholic beverages has been developed from procedures previously reported for application to water samples. Quantitatively isolating HCN from alcoholic beverages presented difficulties not encountered with aqueous solutions, particularly in the presence of SO2 in the sample. HCN was liberated from the acidified sample by heating at 70°C, flushed into an NaOH absorber solution, converted to cyanogen bromide (CNBr), extracted into diisopropyl ether, chromatographed on a Porapak Q column, and detected by an electron capture detector. SO2 that is present in most wines interfered with the bromination step and caused low recoveries. This interference was eliminated by initially converting any cyanide present in the sample to the stable mercuric cyanide salt and then purging the acidified sample solution of all SO2. The Hg(CN)2 present was then dissociated by adding KI and the analysis proceeded as previously described. Mean recoveries of 80–97 % were obtained for 2–20 μg cyanide from replicate analyses of spiked samples of distilled liquors free of SO2. The relative standard deviations ranged from 6.1 to 11.1%. Mean recoveries of 65 to 91% were obtained in the same range of cyanide from replicate analyses of spiked wine samples known to contain SO2, with relative standard deviations ranging from 0.8 to 10.2%. The limit of detection was 0.2 μg HCN.

Gas Chromatographic Determination of O,O-Diethyl S-(N-Isopropylcarbamoylmethyl) Phosphorothiolothionate (Prothoate) in Technical Products and Liquid Formulations

1972 ◽  
Vol 55 (6) ◽  
pp. 1336-1338
Author(s):  
Brunetto Bazzi ◽  
Guglielmo Galluzzi ◽  
Luigi Abruzzese
Keyword(s):  
Thermal Conductivity ◽  
Gas Chromatography ◽  
Chromatographic Method ◽  
Concentration Level ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Thermal Conductivity Detector ◽  
Gas Chromatographic Method ◽  
Technical Products

Abstract A gas chromatographic method has been developed for the analysis of O,O-diethyl S-(N-isopropylcarbamoylmethyl) phosphorothiolothionate . The acaricide or a convenient amount of an acaricidal preparation is dissolved in xylene, together with malathion as an internal standard, and analyzed by gas chromatography, using a thermal conductivity detector. The precision (P = 0.05) of the method is ±1.5% of the concentration level.

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