Shimadzu TOC-V Series, TOC Measurements on Tap Water, TOC Adopted as Water Quality Standard for Tap Water

Introduction

Potassium permanganate consumption has long been used as the organic-matter indicator in the water quality standards for tap water. However, a replacement indicator was required due to problems with the potassium permanganate indicator, including fluctuations in measured values according to the organic matter type, large measurement discrepancies from operator to operator, and poor reproducibility even when a single operator conducts measurements. Total Organic Carbon (TOC) has been recognized as the most effective indicator of organic matter in water in terms of organic matter detection rate, measurement accuracy, and sensitivity. TOC officially replaced potassium permanganate consumption as the organic-matter indicator in the water quality standards on 30 May 2003 in Japan (TOC control value: 5 mgC/L. This replacement is applicable from 1 Apr, 2005). The TOC analyzer used for these measurements must offer two characteristics: sufficient sensitivity to accurately measure TOC in tap water and sufficient oxidation capacity to detect organic suspended solids in raw water. The Shimadzu TOC-V Series analyzers employ combustion oxidation at 680¡C to simultaneously achieve excellent oxidation performance and 4 g/L detection limit sensitivity, regardless of the type of organic matter. This Application News introduces examples of tap-water TOC measurements using a Shimadzu TOC-VCPH combustion oxidation TOC analyzer.

September 8, 2003 GMT