EPA-met314 DETERMINATION OF PERCHLORATE IN DRINKING WATER USING ION
CHROMATOGRAPHY
1. SCOPE AND APPLICATION
1.1 This method covers the determination of perchlorate in reagent water, surface water,
ground water, and finished drinking water using ion chromatography.
1.2 The single laboratory reagent water Method Detection Limit (MDL, defined in Section
3.16) for the above analyte is listed in Table 1. The MDL for a specific matrix may
differ from those listed, depending upon the nature of the sample and the specific
instrumentation employed.
1.2.1 In order to achieve comparable detection limits, an ion chromatographic system
must utilize suppressed conductivity detection, be properly maintained, and
must be capable of yielding a baseline with no more than 5 nanosiemen (nS)
noise/drift per minute of monitored response over the background conductivity.
1.3 This method is recommended for use only by or under the supervision of analysts
experienced in the use of ion chromatography and in the interpretation of the resulting
ion chromatograms.
1.4 When this method is used to analyze unfamiliar samples for perchlorate, anion
identification should be supported by the use of a laboratory fortified matrix sample.
The fortification procedure is described in Section 9.4.1.
1.5 Users of the method data should identify data quality objectives prior to analysis. Users
of the method must demonstrate the ability to generate acceptable results, using the
procedures described in Section 9.0.
1.6 This method specifies an IC column and analytical conditions which were determined
to be the most effective for the widest array of sample matrices. Other IC procedures
have been written which incorporate similar columns and conditions, such as hydroxide
based mobile phases, low hydrophobicity IC columns, and measurement by suppressed
conductivity detection.1-5 During the development of this method, these other
procedures, as well as the columns and conditions outlined in this method, were
concurrently investigated with comparable results for test matrices with moderate levels
of common inorganic background anions. These findings were consistent with those of
the Inter-Agency Perchlorate Steering Committee, Analytical Subcommittee’s Report,6
published in 1998, which reported on the results of an interlaboratory validation of
these other Ion Chromatographic Methods. The columns and conditions identified in
this method were recommended since they bore the greatest tolerance for the highest
levels of common inorganic anion interference.
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