Methods and systems for the detection and quantification of multiplicity of ionic analytes comprising CrO42−, AsO43−, SeO42−, and ClO4−, and optionally F−, Cl−, NO2−, NO3−, SO42−, using ion chromatography and suppressed ion conductivity. The method comprises loading a sample loop with a sample; injecting the sample from the sample loop into a column with an eluent, wherein the column comprises a guard column and an analytical column; separating, with the column, the injected sample at an effective separation temperature the injected sample in the presence of an organic modifier into a multiplicity of detectable ionic analytes; suppressing, with a suppressor, background signal; and detecting, with a detector, the multiplicity of ionic analytes.