Detection and Chemical Analysis of High Purity Water 911480
To establish a database to determine whether selected chemicals, not included in the NCCLS standards, could be detected in point-of-use water treatment systems (POUs), we analyzed water samples collected from 50 POUs following service maintenance. These samples were first analyzed for compliance with NCCLS standards for reagent grade water. A spectrophotometer was then used to analyze product water samples for detectable levels of free and total Cl, ClO2, Cr, Cu, Fe, Mn, NO3, SO4 and Si. The following percentages of water systems had detectable levels chemicals (according to water type). For Type I water, free Cl was found in 89%, total Cl, 50%; ClO2, 11%; Cr, 28%; Cu, 78%; Fe, 33%; Mn, 22%; NO3, 89%, Si, 83%; and SO4, 17%. For Type II water, free Cl was found in 71 %, total Cl, 50%; ClO2, 21%; Cr, 29%; Cu, 63%; Fe, 25%; Mn, 4%; NO3, 54%; and Si, 75%. For Type III water; 63% of the product water samples analyzed had detectable levels of both free and total Cl; 88% Cr and Si; 38% Cu and NO3; and 13%, Fe. These findings illustrate that in many cases selected chemicals are not completely retained during the purification process and that a portion may pass from source water to product water.