A method integrating a long waveguide capillary cell with a preconcentration resin in a multi-syringe flow injection analysis (MSFIA) system for iron determination in waters was developed. The determination of iron is based on a colorimetric reaction and two reagents were tested, ferrozine and ammonium thiocyanate. A liquid waveguide capillary cell (1.0 m pathlength, 550 μm i.d. and 250 μL inte...

A simple micro (0.1 ml.) colorimetric method is described for the determination of serum calcium. This method employs the differential chelating characteristic of glyoxyl bis (2-hydroxyanil) in the presence of other divalent cations. The serum sample is placed in a colorimetric tube followed by additions of water, glyoxyl bis (2-hydroxyanil) reagent, and alkaline carbonate color developer. Chlo...

A comparison of two colorimetric procedures for the determination of serum glutamic oxaloacetic acid (SCOT) showed that both the dinitrophenylhydrazine and diazonium salt colorimetric assay procedures have good precision and reproducibility acceptable to most clinical laboratories. Babson’s diazonium salt procedure (3) definitely shows greater precision in the important borderline range of valu...

A sensitive method is proposed for the colorimetric determination of free fatty acids (FFA). Diphenylcarbazide containing diphenylcarbazone is used as the color developing reagent instead of diethyldithiocarbamate which was employed in the previous method (1965). J. Lipid Res. 6: 16-20). The present method was successfully applied to the determination of FFA present in as little as 40 microlite...

The colorimetric method for the determination of total cholesterol in dog bile is consistently accurate as checked by the oxidative digitonin method. This method has the further advantages of being simple, rapid and economical. A method for the determination of esterified cholesterol in bile is described and it is shown that there are no esters of cholesterol in normal dog bile.

Methods for the determination of fluorine in a variety of matrices are reviewed with particular attention to those techniques which are widely adopted as routine methods. The fluoride ion-sensitive electrode is a very successful potentiometric technique for the determination of fluoride in aqueous solution and it has largely replaced the various colorimetric methods formerly used. However it is...