Alex Post

Identification and quantitation of alditol acetates of neutral and amino sugars from mucins by automated gas-liquid chromatography.

Abstract An automated GLC method has been described that allows easy identification and quantitation on a single column of the alditol acetates of the commonly occurring neutral and amino sugars found in epithelial mucins on a new high-temperature stable column. Due to various losses that occur during the derivatization procedure, a constant, termed LF , must be entered into the calculation of the amount of each sugar present. When this factor is applied, the correlation between colorimetric and GLC results is very good.

Semiautomated Turbidimetric Microbiological Assay for Determination of Cefazolin

The Autoturb System, a semiautomated system for photometric bioassay, was used to determine cefazolin content. Suitable conditions for the assay using Streptococcus faecalis ATCC 10541 as the indicator organism included a medium pH of 6.0 to 7.0 and an incubation time of 3 to 3.5 h at 36 C. Multiple independent assays of samples from a common batch showed the test to be highly reproducible. Accuracy of the turbidimetric assay was evaluated by comparing data obtained from a chemical (hydroxylamine) and a biological (disk diffusion) assay. The available data show the turbidimetric assay to be a rapid, accurate, and reproducible method for determining the biological activity of cefazolin samples.

A micro procedure for the estimation of the protein content of mucus glycoproteins

Abstract A sensitive automated procedure for the estimation of the protein content of glycoproteins has been developed using 0.5-mg samples (10–250 μg of protein). The method employs a modification of the conventional amino acid analysis using the unresolved neutral and acidic amino acid peak to estimate the total protein content. Hexosamines, sialic acid, and amide amino acids do not interfere.

The application of elemental analysis to the determination of the composition of a mixture of pyridine compounds

Abstract The composition of a gross mixture of pyridine compounds was determined rapidly and inexpensively by the use of standard microanalytical techniques. Spectral data corroborated the elemental results.

Quantitative analysis of low levels of chloroform in cough syrups by nuclear magnetic resonance

Abstract A rapid, accurate quantitative method for the determination of chloroform at low levels has been presented. The method requires no prior separation of the chloroform from the cough syrup and eliminates the possibility of loss of chloroform during extraction or distillation procedures.