significance And Use:

scope:

1.1 This procedure covers the determination of aldicarb, carbofuran, oxamyl and methomyl (referred to collectively as carbamates in this test method) in surface water by direct injection using liquid chromatography (LC) and detected with tandem mass spectrometry (MS/MS). These analytes are qualitatively and quantitatively determined by this method. This method adheres to multiple reaction monitoring (MRM) mass spectrometry.

1.2 This test method has been developed by US EPA Region 5 Chicago Regional Laboratory (CRL).

1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.4 The Detection Verification Level (DVL) and Reporting Range for the carbamates are listed in Table 1.

TABLE 1 Detection Verification Level and Reporting Range

1.4.1 The DVL is required to be at a concentration at least 3 times below the Reporting Limit (RL) and have a signal/noise ratio greater than 3:1. Fig. 1 displays the signal/noise ratios of the primary single reaction monitoring (SRM) transitions and Fig. 2 displays the confirmatory SRM transitions at the DVLs for the carbamates.

FIG. 1 Example Primary SRM Chromatograms Signal/Noise Ratios
FIG. 2 Example Confirmatory SRM Chromatograms Signal/Noise Ratios

1.4.2 The reporting limit is the concentration of the Level 1 calibration standard as shown in Table 2 for the carbamates.

TABLE 2 Concentrations of Calibration Standards (PPB)

1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.