THIS REPORT describes a procedure for the automated simultaneous determination of calcium and phosphate and its application to the analysis of 0.3 ml. serum. Calcium is determined fluorometrically as the calcein derivative using a portion of the serum sample. Phosphate is determined spectrophotometrically in an improved flow system which also incorporates a more sensitive reducing reagent, stan...

In the last decade, long path length, low volume, liquid waveguide capillary cells (LWCC) in conjunction with conventional nutrient auto-analyzers have been applied to determinations of nanomolar levels of phosphate, nitrate, and nitrite in oligotrophic waters. This article reports a high resolution, real-time, continuous method for nanomolar dissolved reactive phosphate measurements in ocean s...

a catalytic-kinetic method for the determination of selenium is proposed. alizarin navy blue is reduced by sodium sulfide to from a colorless product. the reaction is accelerated by trace amounts of se (iv), and can be followed by measuring the decrease in absorbance of the dye at 620nm and 30 °c by the fixed time method. selenium can be determined in the range of 0.004 — 0.12 1.1g.m1-1 . ...

A molybdenum reducing bacterium with the novel ability to decolorise the azo dye Metanil Yellow is reported. Optimal conditions for molybdenum reduction were pH 6.3 and at 34°C. Glucose was the best electron donor. Another requirement includes a narrow phosphate concentration between 2.5 and 7.5 mM. A time profile of Mo-blue production shows a lag period of approximately 12 hours, a maximum amo...

A new and convenient method for the determination of P, was developed. Phosphomolybdate is measured calorimetrically, without reduction to molybdenum blue, by dissolving the whole assay mixture in acetone, where phosphomolybdate is bright yellow. The hydrolysis of acidlabile phosphates (e.g., creatine phosphate) causes no problems, because extra molybdate is complexed with citrate immediately a...

Molybdenum(VI) oxide reacts with molten LiC1-KCI eutectie at 450 ~ to form MOO2C12, which probably is present as an anion MoO2Cl4 =, and pyromolybdate, Mo207 =. Both of these species are electrochemically reduced to MOO2, which can be reoxidized to MoO2CI2 by current reversal. A second reduction step, observed whether MoO3 or Mo2072is added to the melt, can be attributed to the reduction of MoO...