The HI93763B-50 reagent kit contains 50 ready-to-use vials of HI93758V-0HR, 1 bottle of HI93758C-0 solution, 1 bottle HI93763B-0 molybdovanadate reagent, and 50 packets of potassium persulfate reagent. These high quality reagents follow an adaptation of the Standard Methods for the Examination of Water and Wastewater, 20^th edition, 4500-P C, vanadomolybdophosphoric acid method. In this method, the persulfate digestion converts organic and condensed inorganic forms of phosphates to orthophosphate. Then the reaction between orthophosphate and the reagents causes a yellow tint in the sample. The amount of phosphorus is then measured colorimetrically. The intensity of color is determined by a compatible photometer and the concentration is displayed in mg/L (ppm) of phosphorus. These reagents are designed to be used with samples that have an expected range of 0.0 to 32.6 mg/L (ppm) phosphorus.

Hanna vials contain pre-dosed reagent so the user simply needs to add a small quantity of the sample, a packet of the potassium persulfate reagent, and heat at 150° F for 30 minutes followed by the addition of the sodium hydroxide solution and the molybdovanadate reagent to determine concentration. With pre-dosed vials, test preparation time is dramatically reduced and there is no time-consuming reagent preparation procedure or glassware cleaning. The vials and caps of the reagents have been designed to avoid accidental reagent spills. Due to the pre-dosed reagents, the amount of chemicals and handling time is also minimized.