The HI95747-03 are high quality reagents that are pre-measured, allowing for users to achieve fast and accurate colorimetric measurements. The method is an adaptation of the USEPA approved bicinchoninate method. The reaction between copper and the reagent causes a color change in the sample. By simply adding the reagent to the sample, a reaction will take place and a compatible photometer can be used to determine the concentration from the color that is produced. The unit results will be displayed as μg/L (ppb) or mg/L (ppm) of copper. These reagents are designed to be used with freshwater samples that have an expected range of 0 to 1000 μg/L copper for the benchtop photometers and 0.000 to 1.500 mg/L for the portable photometer.