The HI94758C-50 reagent kit contains 50 ready-to-use vials of HI94758V-0, 1 bottle of HI93758C-0 solution, 50 packets of potassium persulfate reagent, and 50 packets of HI93758-0 phosphorus reagent. These high quality reagents follow an adaptation of the EPA method 365.2 and Standard Methods for the Examination of Water and Wastewater, 20th edition, 4500-P E, ascorbic acid method. In this method, a persulfate digestion converts organic and condensed inorganic forms of phosphates to orthophosphate then the reaction between orthophosphate and the reagent causes a blue 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 0.00 to 1.15 mg/L (ppm) phosphorus.

Hanna vials contain pre-dosed reagent so the user simply needs to add a small quantity of the sample to the vial along with a packet of the potassium persulfate reagent followed by heating 30 minutes at 150°C and cooling, then the addition of the NaOH solution to use as the blank, followed by the addition of the phosphorus powder reagent to measure the 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. These vials feature Hanna’s barcode recognition system exclusive to the HI83224 Wastewater Treatment benchtop photometer. The meter scans each vial to automatically identify sample method and range. The barcode has four digits: the first two digits are for parameter identification and the second two digits are for reagent lot ID. Vials for different methods can be distinguished by a barcode printed on the vial and the cap color.