The goal of this research was to develop a U.S. Environmental Protection Agency method for the determination sub-ppb
concentrations of the perchlorate anion (ClO<sub>4</sub> <sup>-</sup>) in drinking waters and in waters high in total
dissolved solids. To date, ion chromatography using a KOH mobile phase, electrolytic
conductivity suppression (Dionex Corporation, Sunnyvale, CA) and electrospray ionization mass
spectrometric detection (ThermoFinnigan, San Jose, CA) has been explored with the following
salient features:
low-level linear calibration from 0.01 - 1.0 ppb with an R<sup>2</sup> ≥0.999;
method detection limits (MDLs) in deionized and high ionic waters (up to 1000 ppm
common anions sulfate, chloride and carbonate) from 0.03 - 0.11 ppb with no significant
difference between MDLs when using mass 99 or mass 101 as quantitation ions at =0.01;
precision of replicate injections at 1 ppb was less than 5% relative standard deviation on
masses 99 and 101 on a daily basis;
accuracy as determined by analysis of a certified reference material was ±5% of certified
value in deionized water; and,
ruggedness as determined by the reproducibility of area counts of 1.0 ppb check standards
analyzed periodically over a day of continuous analysis of high ionic matrices revealed
some deterioration of signal intensity (~15% drop). Simple measures were implemented to
preserve signal intensity over time and in high ionic matrices. Includes 2 references.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 290 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 4 |
| Published : | 11/02/2003 |
