Environ. Sci. Technol. 2000, 34, 4454
Response to Comment on “Perchlorate Identification in Fertilizers” and the Subsequent Addition/Correction SIR: As Urbansky et al. (1) acknowledge, our original report (2) of high levels of perchlorate in virtually all lawn and garden fertilizers that we tested (which were acquired from November 1998 to January 1999) is now undisputed. At this point, these positive identifications have been supported by four well-established analytical techniques (ion chromatography, NMR spectroscopy, capillary electrophoresis, and Raman spectroscopy), from four separate samplings, going back each time to the original bags, and by three separate laboratories. However, like Urbansky et al. (1), we find and have reported (3) that virtually all products of the same type * Corresponding author telephone: (706)355-8235; fax: (706)3558202; e-mail:
[email protected].
4454 9 ENVIRONMENTAL SCIENCE & TECHNOLOGY / VOL. 34, NO. 20, 2000
acquired after July 1999 do not contain perchlorate above the ion chromatographic detection level. We have not yet determined the source of contamination of the earlier products.
Literature Cited (1) Urbansky, E. T.; Magnuson, M. L.; Kelty, C. A.; Gu, B.; Brown. G. M. Environ. Sci. Technol. 2000, 34, 4452-4453. (2) Susarla, S.; Collette, T. W.; Garrison, A. W.; Wolfe, N. L.; McCutcheon, S. C. Environ. Sci. Technol. 1999, 33, 3469-3472. (3) Susarla, S.; Collette, T. W.; Garrison, A. W.; Wolfe, N. L.; McCutcheon, S. C. Environ. Sci. Technol. 2000, 34, 224.
Sridhar Susarla, T. W. Collette, A. W. Garrison, N. L. Wolfe, and S. C. McCutcheon* United States Environmental Protection Agency National Exposure Research Laboratory Ecosystems Research Division 960 College Station Road Athens, Georgia 30605 ES0020097
10.1021/es0020097 Not subject to U.S. copyright. Publ. 2000 Am. Chem.Soc. Published on Web 09/09/2000
