doi: 10.1080/00032719208018517pmid: N/A
Abstract This is a scanned image of the original Editorial Board page(s) for this issue.
Ding, Thomas; Bilitewski, Ursula; Schmid, Rolf D.
doi: 10.1080/00032719208018518pmid: N/A
Abstract The metabolic activity of the lactic acid bacteria Lactobacillus plantarum and Leuconostoc mesenteroides were determined in mixed cultures by a bioelectrochemical method. Several artificial electron acceptors were tested for their reaction with the two strains. By use of three suitable mediators (potassium hexacyano-ferrate(III), 2,6-dichlorophenolindophenol, toluidin blue O) patterns were measured electrochemically reflecting the microbial reduction of the mediators. A relationship between composition of the mixed cultures and shape of the patterns was observed after an optimal reaction time of 12 min.
Navaratne, Ayanthi; Rechnitz, Garry A.
doi: 10.1080/00032719208018519pmid: N/A
Abstract The use of a novel thin layer electrode design, with a plant tissue reactor and a sensing tin oxide collector electrode, is proposed for amperometric detection in flow injection analysis and compared with previous carbon paste electrode designs. The new system, evaluated for the case of catechol measurements, is shown to offer superior sensitivity, dynamic range and detection limits.
G., Talbot B.; R., Anderson D.; W., Harris L.; J., Lennox W.
doi: 10.1080/00032719208018520pmid: N/A
Abstract We have developed a radiometric method (I) for measuring cholinesterase (ChE) activity that uses 0.4 N perchloric acid (PCA), instead of p-dioxane (method II), to denature the ChE and stop hydrolysis of acetyl-1-14C-choline (ACh). The unreacted ACh is removed by IRP-69 cationic exchange resin suspended in water, instead of dioxane. The supernatant (acidic water solution) containing the hydrolysis product, 14C-acetic acid, is mixed with nonhazardous scintillation cocktail and counted. The incubation mixture (37°C) of I is similar to II and contains 0.1 ml of buffer-salt solution (pH 7.8), 0.1 ml of guinea pig whole blood (WE)-water suspension and 0.1 ml of 3 mM ACh solution. Procedures I and il were compared to a titragraphic assay for ChE activity; specific activity values of WB (mmol ACh hydrolyzed/ml/hr) were found to be 137.6, 72.4 and 135.0, respectively.
Priest, D. G.; Bunni, M. A.; Mullin, R. J.; Duch, D. S.; Galivan, J.; Rhee, M. S.
doi: 10.1080/00032719208018521pmid: N/A
Abstract Two different analytical methods were used to estimate reduced folates from the same cultured hepatoma cell preparation. A method based on HPLC separation of reduced folate pools in cells prelabelled with [3H]-folic acid was compared to a method based upon quantitative assessment of bound radioactive ligand by gel filtration after entrapment of one reduced folate, methylenetetrahydrofolate, into a stable ternary complex with thymidylate synthase and [3H]-fluorodeoxyuridine monophosphate. In this second method additional folate pools were measured following enzymatic conversion to methylenetetrahydrofolate. Results show completely satisfactory agreement between the two methods both in terms of total folate content and in levels of individual folate pools.
doi: 10.1080/00032719208018522pmid: N/A
Abstract An overview of various cellulose-based chiral stationary phases (CSP's) which are commercially available for direct separation of drug racemates to their corresponding enantiomers is presented. The advantages, disadvatanges, and mechanisms of resolution of these CSP's are briefly discussed. Examples of baseline resolution of some drug racemates are presented and the number of successful resolutions on these CSP's is increasing rapidly.
Elsayed, M. Abdel-Hady; Korany, Mohammed A.; Bedair, Mona M.; Mahgoub, Hoda; Korany, Ezzat A.
doi: 10.1080/00032719208018523pmid: N/A
Abstract Two mixtures (caffeine mixture (I) and codeine mixture (II)) of 3-components, containing acetaminophen and salicylamide as majors, have been assayed using different computer-assisted spectrophotometric methods. These methods are the Unique Absorbance Method (UAM), the Unique Orthogonal Function Method (UOFM), and Unique Fourier Function Method (UFFM), and also their correspondences under the least squares approach. The parameters have been optimized for the accurate determination of the minor component caffeine in mixture (I). In mixture (II), however. codeine has been extracted - in two steps-prior to the correction of interferences from the major components acetaminophen and salicylamide.
Cruz, A.; Bermejo, A.; López-Rivadulla, M.; Fernández, P.
doi: 10.1080/00032719208018524pmid: N/A
Abstract A spectrophotometric method for the simultaneous determination of methaqualone and diazepam in plasma by second-derivative spectroscopy is reported. The proposed method is quite sensitive (it allows the determination of therapeutic levels of both pharmaceuticals) and easy to implement. It provided average recoveries of 93.75% and 99.04% for methaqualone and diazepam, respectively.
doi: 10.1080/00032719208018525pmid: N/A
Abstract Two simple and sensitive spectrophotometric methods are described for the quantitative determination of ethambutol. The first method is based on the reaction between dichlorophenol indophenol (DCPIP) and ethambutol to give bluish violet radical ions exhibiting maximum absorption at 640 nm. The second method depends upon the formation of yellow colored ethambutol picrate measurable at 430 nm. Obedience of both chromogens to Beer's law permits the ethambutol determination in pharmaceutical preparation with high accuracy and good reproducibility.
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