No abstract

A gas-liquid chromatographic method for measurement of diphenylhydantoin in serum has been developed. In this procedure the diphenylhydantoin is extracted from acidified serum with chloroform. After formation of the methoxy derivative, separation and measurement are accomplished by gas chromatography using a flame ionization detector. The method has the advantages of considerable specificity and sensitivity. Results obtained by this procedure compared favorably with measurements made by the Svensmark-Kristensen colorimetric procedure' for determination of diphenylhydantoin.

ExtractConcentrations of free and conjugated bile acids in cord blood (30 samples) were within the adult range and were significantly higher than in serum from newborns (15 infants). Deoxycholic acid (D) was absent from sera of newborns and present in 7 of 23 cord samples. Only two of nine infants in year 1 of life showed detectable amounts of D. In 25 children, ages 1-13 years, bile acid concentrations in serum fell within the normal adult range. Small amounts of unconjugated bile acids were present in some specimens.Thirty-three children with cystic fibrosis of the pancreas (ages 2-14 years) had serum concentrations within the normal adult range. No correlation with age, sex, or severity of disease was noted.Thirty-two children with a variety of hepatobiliary disorders had significantly elevated concentrations of bile acids with the exception of a few infants with terminal cirrhosis. Determination of patterns and concentrations of bile acids in serum are of limited usefulness in differential diagnosis of these disorders. Speculation

A gas-liquid chromatographic method for chloramphenicol in serum has been described which uses electron capture spectrometry for quantitative measurement. In this procedure chloramphenicol was extracted from the serum gith isoamyl acetate and the ditrimethylsilyl ether was formed and chromatographed. The method has speed, simplicity, specificity, and accuracy. A comparison of this procedure with two other chemical assays was made which provided further evidence of the specificity of this method. ECAUSE of evidence relating chlor-