Determination of phosphate in serum and urine by a single step malachite-green method.

The highly sensitive malachite-green method for the determination of phosphate requires a protective colloid in order to avoid precipitation of the formed dye salt. A polyvinylalcohol proved to be suitable and permit the determination of phosphate in urine and in serum without prior precipitation of the proteins. The present method is suitable for a one-step procedure which allows the analysis of several hundred samples per man-hour and is applicable to microquantities of serum or urine.