Three methods are presented here for the determination of Chromium in various matrices. Method A utilizes a postcolumn reaction (PCR) with a color reagent. It is a very selective and sensitive method, allowing determination of Cr(III) & Cr(VI) at ppb levels. Method B also utilizes a PCR, but determines Cr (VI) only. It is used for industrial waste waters, analyzing samples that have undergone standard oxidation. Method C allows the determination of inorganic anions in addition to chromate by chemically suppressed conductivity. Please refer to AN1116, AU144, AU165 and AU179 for updated methods.

Metal cyanide complexes are of environmental concern because they release cyanide upon dissociation. The metal cyanide complexes of silver, gold, copper, nickel, iron, and cobalt are separated on an IonPac AS11 column and quantified by measuring their absorbance at 215 nm. Use of the 2-mm AG11/AS11 column set provides different selectivity, lower eluent use, and better solvent compatibility than the AG5/AS5 column set featured in AN 55. The method was evaluated for reproducibility, linearity, accuracy, precision, and spike recovery from various matrices.

In this updated method, the perchlorate anion is determined in 15 min by using a 2 mm Dionex IonPac AS16 column, EG50-generated hydroxide eluent, a 1000 μL injection, and suppressed conductivity detector. The resulting single-operator method detection limit (MDL) for perchlorate in a simulated high-ionic-strength water sample was 0.10 μg/L after sample preparation.

Hexavalent chromium, Cr(VI), is the most toxic form of chromium, a primary drinking water contaminant in the U.S. Cr(VI) can be determined as chromate by ion chromatography in drinking water, and wastewater.The California Department of Health Services recently issued a new Public Health Goal of 0.2 µg/L for Cr(VI). EPA Method 218.6 does not allow sufficient sensitivity for analysis at the California PHG level. This update describes modifications to Method 218.6 that significantly increase sensitivity over the existing method.Also refer to AU 179 for an updated method.

The Thermo Scientific TRACE GC Ultra is applied for the analysis of aliphatic hydrocarbons in diesel and gasoline range organics in ground and surface water by EPA method 8015. The separation was performed on a Thermo Scientific TraceGOLD TG-5SilMS GC column, with MS detection.