doi: 10.1080/00032718308065224pmid: N/A
Abstract This is a scanned image of the original Editorial Board page(s) for this issue.
doi: 10.1080/00032718308065225pmid: N/A
Abstract A reliable procedure for determining Span 20 (Atlas Powder Company, Dallas) concentrations in human plasma samples is presented. The samples are extracted with diethyl ether and saponified with methanolic KOH. The liberated fatty acids (specifically, lauric and myristic acids) are acidified, extracted with diethyl ether, methylated using ethereal diazomethane, and subsequently quantitated using gas-liquid chromatography with pentadecylic acid as an internal standard. Under the conditions employed, methyl esters of lauric and myristic acids have retention times of approximately 0.9 min and 1.9 min, respectively. The results with this method were found to be linear over the range of concentrations studied, that is, between 1.0 and 500 μ/ml. The correlation coefficients of the standard curves were greater than 0.99 and the coefficient of variation about any individual point was less than 10%.
Renneberg, Reinhard; Scheller, Frieder; Riedel, Klaus; Litschko, Eckhard; Richter, Manfred
doi: 10.1080/00032718308065226pmid: N/A
Abstract A glucose oxidase-glucoamylase-bienzyme electrode has been developed and tested for determination of α-amylase activity. To eliminate interfering endogeneous glucose a glucose oxidase-catalase anti-interference layer was coupled with the bienzyme electrode. Linearity was obtained for the kinetic signal up to 1.0 I.U. α-amylase. Glucose was effectively eliminated up to 2 mM final concentration thus not influencing α-amylase determinations. A general concept for anti-interference enzyme layers is suggested.
El-Din, Ahmed A. Seif; Korany, Mohamed A.; Abdel-salam, Nabil A.
doi: 10.1080/00032718308065227pmid: N/A
Abstract A rapid and simple method for determining cinnamic aldehyde in cinnamon and cassia oils and carvone in caraway and dill oils is presented. These oils are diluted with ethanol and their respective constituents are directly determined by measuring peak-trough amplitudes of the generated second derivative spectra at certain wavelengths. The results obtained are reasonably reproducible with a coefficient of variation less than 2%.
Mason, William D.; Gillilan, Roberta
doi: 10.1080/00032718308065228pmid: N/A
Abstract The method for the analysis of aspirin and salicylic acid in human plasma has been updated to include advances in column technology, extraction procedures and absorbance detection. Aspirin and salicylic acid are extracted from acidified plasma into an organic solvent system containing internal standard. Following controlled evaporation under partial vacuum of the organic extract, the dried down-residue is reconstituted with mobile phase. Chromatography is ion suppression reverse phase on a 5 μm O.D.S. column with detection by absorbance at 237 nm and optional fluorescence. Concentration of aspirin as low as 0.20 μg/ml and salicyclic acid as low as 0.50 μg/ml can be quantitated.
Shah, Mumtaz H.; Stewart, James T.
doi: 10.1080/00032718308065229pmid: N/A
Abstract A flow-injection method for the determination of isoniazid based on electrochemical oxidation at the glassy carbon electrode is presented. The amperometric method is highly specific and may be used to determine isoniazid in the presence of most other drugs and/or preservatives commonly found in its pharamaceutical dosage forms or administered concurently in therapeutic situations. Using an electrode potential of +825 mV, a calibration curve is linear (r = 0.9999) in the 0.05-6 μg/ml concentration range with minimum detectability at 0.5 ng (S/N = 2). The method applied to the analysis of isoniazid in a pharmaceutical dosage form shows good accuracy and precision. Although automation was not used in this study, the method could readily be incorporated in automated systems because it employs the technique of continuous analysis in a flowing stream.
Wang, Joseph; Dewald, Howard D.
doi: 10.1080/00032718308065230pmid: N/A
Abstract Anodic stripping voltammetry is applied for measurement of copper and zinc in pharamaceutical formulations. Because of the inherent sensitivity and selectivity of stripping voltammetry toward amalgam forming metals, no sample preparation is required (except for acidic dissolution). Copper-zinc intermetallic interferences are eliminated by the addition of an excess of gallium or through utilization of a dual working electrode approach. Automation of this procedure is indicated from flow injection measurments at a rate of 15 per hour.
doi: 10.1080/00032718308065231pmid: N/A
Abstract An HPLC method for analysis of atenolol in human plasma and urine is presented. Based on alkaline extraction, acid backextraction and reverse phase ion-pair chromatography this method is quite specific for atenolol. For a 0.5 ml plasma sample the sensitivity ranges from 20 ng/ml in fasted healthy volunteers to 50 ng/ml in various groups of patients. A sensitivity in urine of 1.0 mcg/ml was sufficient for all samples studied. As presented this method has been used in several clinical pharmacokinetic studies involving hundreds of samples.
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