You are here:
DEVELOPMENT AND VALIDATION OF AN ION CHROMATOGRAPHIC METHOD FOR DETERMINING PERCHLORATE IN FERTILIZERS
Citation:
Urbansky*, E T., T W. Collette, AND W. P. Robarge. DEVELOPMENT AND VALIDATION OF AN ION CHROMATOGRAPHIC METHOD FOR DETERMINING PERCHLORATE IN FERTILIZERS. Presented at Association of Official Analytical Chemists International meet, Kansas City, MO, 9/12/2001.
Description:
A method has been developed for the determination of perchlorate in fertilizers. Materials are leached with deionized water to dissolve any soluble perchlorate compounds. Ion chromatographic separation is followed by suppressed conductivity for detection. Perchlorate is retained on the column (Dionex IonPac AG16/AS16 or equivalent), while other common anions (e.g., phosphate, nitrate, sulfate, chloride) are not. However, the large salt content of the fertilizer matrix affects the background conductivity and produces a large tailing peak from the initial overload of the column. Because the perchlorate peak itself sits on this tail, it can be difficult to quantitate. Limits of detection are substantially matrix-dependent. A number of parameters are left up to the analyst, with guidance on how to choose among the options. Performance and quality control requirements have been established. Results are presented from a multiple laboratory validation. While the method may be optimized for a specific matrix, there is no single set of optimal conditions in terms of obtaining the best detection limits or minimizing false positives/negatives. Overall, the method is suitably rugged and reliable. There is satisfactory agreement among results obtained by various laboratories.