Perchlorate anion (ClO4-) is a contaminant of surface and groundwaters in locations
throughout the world, primarily as a result of military and industrial activities.
Perchlorate has known thyroid activity and has been used as a pharmaceutical to treat
hyperthyroidism. Perchlorate, as ammonium perchlorate, is a powerful oxidant used in
solid rocket fuels; hence, sources of contamination generally occur near military test sites
and chemical manufacturing plants. Perchlorate has also been detected in South
American based fertilizers due to natural deposits. Likewise, some perchlorate has been
detected in US waters where no known military or industrial activity has taken place.
Often these levels are quite low and may not be detectable by traditional analytical
methodology. The most commonly used method is EPA 314, which has a reporting limit
of 4 mg/L. A novel analytical method has been developed which utilizes liquid
chromatography with tandem mass spectrometry (LC/MS/MS) to accurately measure
trace (ng/L) levels of the perchlorate anion. This technique is extremely sensitive and
selective with a resulting method reporting limit of 0.050 mg/L with only a 10 mL
injection volume. This technique can also detect chlorate, iodate, and bromate anions
simultaneously with similar sensitivities. Using this new technique, several surface,
ground, and bottled waters were analyzed. In some waters previously thought to have no
perchlorate contamination, detectable concentrations ranging from 0.050 - >0.300 mg/L
were discovered. Several commercially available bottled waters were testing and over
30% contained detectable levels of perchlorate with concentrations ranging from 0.050 -
0.170 mg/L. Additionally, many of these bottled waters were found to contain bromate at
levels as great as 80 mg/L. The need for low-level analytical methods is of significant
importance considering the EPA draft reference dose for perchlorate of 1 mg/L for
drinking water. Furthermore, more sensitive analytical tools provide data necessary for
more detailed fate and transport information. Using a slight variation to the drinking
water method, this analytical method can also be used for measuring perchlorate in tissue
samples. Using this method, it was determined that perchlorate did not appreciably
bioconcentrate in the tissues of fish, with resulting bioconcentration factors always less
than one. The method described here is robust, rapid, and requires less than one mL of
sample volume, and is easily adapted for using with solid matrices such as animal tissues. Includes 26 references, tables.
| Edition : | Vol. - No. |
| File Size : | 1
file |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 9 |
| Published : | 11/15/2004 |
