Capillary gas chromatography of trimethyl- and methylethylbiphenyls

1980 ◽  
Vol 45 (11) ◽  
pp. 2919-2926 ◽  
Author(s):  
Jan Novrocík ◽  
Marta Novrocíková
Keyword(s):  
Gas Chromatography ◽  
Liquid Chromatography ◽  
Stationary Phases ◽  
Correlation Coefficients ◽  
Gas Liquid Chromatography ◽  
Polar Medium ◽  
Alkyl Groups ◽  
Straight Line ◽  
Isomeric Methyl

Capillary gas-liquid chromatography with three columns impregnated with non-polar, medium and polar stationary phases has been used for determination of the Kováts indexes of methylethyl- and trimethylbiphenyls carrying the alkyl groups in the both rings. From elution data of isomeric methyl- and ethylbiphenyls the increments of methyl and ethyl groups have been determined, the theoretical Kováts indexes of the mentioned methylethyl- and trimethylbiphenyls have been calculated, and possibility of prediction and assessment of the Kováts indexes of these substances has been discussed. Parameters of the straight line given by the relation IApiez.L = k . Istat.phase(2) + q have been determined, and correlation coefficients of these relations have been estimated.

Preparation and capillary gas chromatography of polymethyl- and ethylmethylbiphenyls and polymethyldiphenylmethanes

1984 ◽  
Vol 49 (1) ◽  
pp. 218-230 ◽  
Author(s):  
Jan Novrocík ◽  
Marta Novrocíková ◽  
Jaroslav Foniok
Keyword(s):  
Gas Chromatography ◽  
Aromatic Hydrocarbon ◽  
Aromatic Hydrocarbons ◽  
Capillary Gas Chromatography ◽  
Stationary Phases ◽  
Correlation Coefficients ◽  
Polar Medium ◽  
Aromatic Substrates ◽  
Alkyl Groups ◽  
Isomeric Methyl

Trimethyl-, tetramethyl-, and ethylmethylbiphenyls with the alkyl groups at one aromatic ring have been prepared by the Gomberg reaction and identified by capillary gas chromatography. The products are either chemical individua or mixtures of up to three isomers depending on choice of the aromatic hydrocarbon. The ethylmethylbiphenyls have been prepared as mixed standards only. Most aromatic hydrocarbons used in the Gomberg reaction have been prepared by combination of rectification and sulphonation procedures. The HMO method has been used for calculation of the values of the radical superdelocalizabilities at individual centres of the 1,2,4- and 1,2,3-trimethylbenzene molecules which have been compared with product composition of the Gomberg reactions of these hydrocarbons. Reactivities of the aromatic substrates used in the Gomberg reaction have been compared by the competition technique. Capillary gas chromatography using three columns wetted with non-polar , medium, and polar stationary phases has been used to determine the Kovats indexes of the hydrocarbons prepared and parameters of the linear dependences IApiez.L = k.Istat.phase(2) + q (with the corresponding correlation coefficients). From the elution data of the isomeric methyl- and ethylbiphenyls the increments have been derived for methyl and ethyl groups, and possibility of prediction and assessment of the Kováts indexes of polyalkybiphenyls and dimethyldiphenylmethanes is discussed.

DETERMINATION OF PLASMA OESTRIOL IN NORMAL PREGNANCY AND LABOUR USING GAS-LIQUID CHROMATOGRAPHY

1971 ◽  
Vol 51 (3) ◽  
pp. 447-454 ◽  
Author(s):  
W. COOPER ◽  
M. G. COYLE ◽  
J. A. MILLS
Keyword(s):  
Gas Chromatography ◽  
Liquid Chromatography ◽  
Quantitative Determination ◽  
Internal Standard ◽  
Normal Pregnancy ◽  
Gas Liquid Chromatography ◽  
Chemical Purification ◽  
Peripheral Plasma ◽  
Pregnancy And Delivery

SUMMARY A method is described for estimating oestriol in 2–10 ml samples of human pregnancy peripheral plasma. It incorporates acid hydrolysis, chemical purification, methylation, chromatography on alumina columns, formation of a derivative and quantitative determination by gas chromatography. A radioactive internal standard was added to correct for procedural losses. Plasma oestriol determinations in five normal patients throughout pregnancy and delivery are reported.

Quantitation of anticonvulsant drugs in serum by gas-chromatography on the stationary phase SP-2510.

1978 ◽  
Vol 24 (3) ◽  
pp. 483-485 ◽  
Author(s):  
W Godolphin ◽  
J Thoma
Keyword(s):  
Gas Chromatography ◽  
Liquid Chromatography ◽  
Stationary Phase ◽  
Serum Cholesterol ◽  
Anticonvulsant Drugs ◽  
Gas Liquid Chromatography ◽  
Column Packing ◽  
Extraction Procedures

Abstract A new column packing, SP-2510 DA (Supelco, Inc., Bellefonte, Pa. 16823), is an excellent stationary phase for the determination of a wide variety of anticonvulsant drugs by gas--liquid chromatography without derivatization. However, when uncomplicated extraction procedures are used, serum cholesterol interferes with the determination of primidone. By the simple expedient of adding a short "pre-column" containing another phase (SP-2250 DA) the problem is overcome.

Monitoring drug concentrations in a case of combined overdosage with primidone and methsuximide.

1976 ◽  
Vol 22 (6) ◽  
pp. 915-921 ◽  
Author(s):  
G F Johnson ◽  
C J Least ◽  
J W Serum ◽  
E B Solow ◽  
H M Solomon
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Liquid Chromatography ◽  
Gas Chromatography Mass Spectrometry ◽  
Gas Liquid Chromatography ◽  
Therapeutic Decision ◽  
Serum Samples ◽  
Monitoring Drug ◽  
Drug Concentrations

Abstract We describe a case of fatal overdosage with primidone and methsuximide. During the early phase of the patient's hospital course we found concentrations of methsuximide, N-desmethylmethsuximide, and primidone in serum that far exceeded the usual therapeutic concentrations, as determined by gas-liquid chromatography. Determination of N-desmethylmethsuximide in peritoneal fluid demonstrated concentrations comparable to those in serum. This led to the therapeutic decision to manage the patient by dialysis. Subsequently, serum samples collected during the course of hospitalization were analyzed quantitatively by gas-liquid chromatography for methsuximide, N-desmethylmethsuximide, primidone, phenobarbital, and diphenylhydantoin. Selected serum specimens were also analyzed by gas chromatography-mass spectrometry, and N-methyl-2-hydroxymethyl-2-phenylsuccinimide, a metabolite of methsuximide not previously described in human serum, was identified by analysis of its mass spectrum.

Radioimmunoassay, enzyme immunoassay, spectrophotometry, and gas-liquid chromatography compared for determination of phenobarbital and diphenylhydantoin.

1976 ◽  
Vol 22 (6) ◽  
pp. 749-753
Author(s):  
V Spiehler ◽  
L Sun ◽  
D S Miyada ◽  
S G Sarandis ◽  
E R Walwick ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Enzyme Immunoassay ◽  
Correlation Coefficients ◽  
Gas Liquid Chromatography ◽  
Ultraviolet Spectrophotometry ◽  
Epileptic Patients ◽  
Quantitative Results ◽  
Analytical Procedures

Abstract Sera from epileptic patients were assayed for phenobarbital and diphenylhydantoin by four different analytical procedures. Quantitative results obtained by radioimmunoassay (I) and enzyme immunoassay (II) were compared to each other and to the results obtained on aliquots of the same sample by gas-liquid chromatography (III) and ultraviolet spectrophotometry (IV). For phenobarbital the correlation coefficients were I vs. II, 0.909; I vs. III, 0.947; II vs. III, 0.917; I vs. IV, 0.950; II vs. IV, 0.953. For diphenylhydantoin the correlation coefficients were I vs. II, 0.953; I vs. III, 0.951; II vs. III, 0.957; I vs. IV, 0.862; II vs. IV, 0.898. The immunoassays can be substituted for liquid chromatography or ultraviolet spectrophotometry without changing the resulting clinical interpretations.

Radioimmunoassay, enzyme immunoassay, spectrophotometry, and gas-liquid chromatography compared for determination of phenobarbital and diphenylhydantoin.

1976 ◽  
Vol 22 (6) ◽  
pp. 749-753 ◽  
Author(s):  
V Spiehler ◽  
L Sun ◽  
D S Miyada ◽  
S G Sarandis ◽  
E R Walwick ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Enzyme Immunoassay ◽  
Correlation Coefficients ◽  
Gas Liquid Chromatography ◽  
Ultraviolet Spectrophotometry ◽  
Epileptic Patients ◽  
Quantitative Results ◽  
Analytical Procedures

Abstract Sera from epileptic patients were assayed for phenobarbital and diphenylhydantoin by four different analytical procedures. Quantitative results obtained by radioimmunoassay (I) and enzyme immunoassay (II) were compared to each other and to the results obtained on aliquots of the same sample by gas-liquid chromatography (III) and ultraviolet spectrophotometry (IV). For phenobarbital the correlation coefficients were I vs. II, 0.909; I vs. III, 0.947; II vs. III, 0.917; I vs. IV, 0.950; II vs. IV, 0.953. For diphenylhydantoin the correlation coefficients were I vs. II, 0.953; I vs. III, 0.951; II vs. III, 0.957; I vs. IV, 0.862; II vs. IV, 0.898. The immunoassays can be substituted for liquid chromatography or ultraviolet spectrophotometry without changing the resulting clinical interpretations.

High-pressure liquid chromatography and enzyme immunoassay compared with gas chromatography for determing phenytoin.

1977 ◽  
Vol 23 (9) ◽  
pp. 1764-1766 ◽  
Author(s):  
R T Chamberlain ◽  
D T Stafford ◽  
A G Maijub ◽  
B C McNatt
Keyword(s):  
Gas Chromatography ◽  
High Pressure ◽  
Liquid Chromatography ◽  
Enzyme Immunoassay ◽  
Correlation Coefficients ◽  
Chromatographic Technique ◽  
Labor Costs ◽  
Gas Chromatographic Method ◽  
Liquid Chromatographic

Abstract We compared a gas-chromatographic method for determination of phenytoin with a high-pressure liquid chromatographic technique and with enzyme immunoassay by three instrumental procedures. More than 100 sera from patients being treated with this drug were assayed by all these techniques. The coefficient of variation was the lowest (4.0%) with liquid chromatography, but all methods gave a CV of less than 10%. The correlation coefficients for all methods exceeded 0.97 when compared to gas chromatography. Operation costs varied with the number of tests per batch, reagent costs, and operator labor costs. All assays gave comparable values for the therapeutic range, so it would be plausible to use more than one method in a situation where (e.g.) satellite laboratories handle different quantities of assays. In any of these techniques, interferences from carbamazepine, mephenytoin, phenobarbital, and primidone were negligible.

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