The HI93740-01 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 1-(2-pyridylazo)-2-naphthol (PAN) method. The reaction between nickel and the reagents causes an orange tint in the sample. By simply adding the reagents to the sample, a reaction will take place and a compatible benchtop or portable meter can be used to determine the concentration from the color that is produced. The results will be displayed in mg/L (ppm) of nickel. These reagents are designed to be used with samples that have an expected range of 0.000 to 1.000 mg/L nickel.