Highly Sensitive Analysis of Chromium (VI) in Drinking Water by Ion Chromatography (IC) with Post-Column Derivatization and UV/VIS Detection

Poster Presentation

Prepared by D. Mazawa, R. Smith, S. Nerkar, M. Ofitserova
Pickering Laboratories, Inc., 1280 Space Park Way, Mountain View, California, 94043, United States


Contact Information: david.mazawa@pickeringlabs.com; 650-694-6700


ABSTRACT

HIGHLY SENSITIVE ANALYSIS OF CHROMIUM (VI) IN DRINKING WATER BY ION CHROMATOGRAPHY (IC) WITH POST-COLUMN DERIVATIZATION AND UV/VIS DETECTION
Chromium is widely used in the manufacturing of metal alloys, surface coatings, pigments and other products. It is also present naturally in soil. Chromium (VI) is the most toxic form of Chromium and is a possible human carcinogen. Due to its high solubility, Hexavalent Chromium can easily contaminate drinking and ground water sources and its levels must be monitored.
In July 2011, the Office of Environmental Health Hazard Assessment (OEHHA) established a Public Health Goal (PHG) for Chromium (VI) at a concentration of 0.02 ug/L. Based on the PHG, the California Department of Public Health is developing a primary drinking water standard (Maximum Contaminant Level, MCL) that is specific for Chromium (VI).
EPA Method 218.7 uses post-column derivatization with diphenylcarbazide under highly acidic conditions and UV/VIS detection to analyze Chromium (VI) in drinking water. Injection volumes of 1000 uL and 1250 uL were used in the method but Pickering Laboratories was able to meet method requirements with as low as 100 uL injections. Modern IC systems and columns can successfully separate Chromium (VI) from other ions with short run times. Pickering Laboratories’ post-column system is uniquely suitable for delivering aggressive derivatizing reagents with unmatched flow precision and low noise level in order to consistently provide highly sensitive detection of Hexavalent Chromium.