N-methylcarbamates and n-methylcarbomoyloximes are used in agriculture as insecticides and herbicides. They are sometimes found in both surface and ground waters and can be toxic to animals and plants at moderate to high concentrations. The manufacturing precursors and degradation products may be equally as hazardous to the environment.

1.1 This is a high-performance liquid chromatographic (HPLC) test method applicable to the determination of certain n-methylcarbamoyloximes and n-methylcarbamates in ground water and finished drinking water (). This test method is applicable to any carbamate analyte that can be hydrolyzed to a primary amine. The following compounds have been validated using this test method: Numbering system of Chemical Abstracts, Inc.

Analyte	Chemical Abstract Services Registry Number
Aldicarb	116-06-3
Aldicarb sulfone	1646-88-4
Aldicarb sulfoxide	1646-87-3
Baygon	114-26-1
Carbaryl	63-25-2
Carbofuran	1563-66-2
3-Hydroxycarbofuran	16655-82-6
Methiocarb	2032-65-7
Methomyl	16752-77-5
Oxamyl	23135-22-0

1.2 This test method has been validated in a collaborative round-robin study () and estimated detection limits (EDLs) have been determined for the analytes listed in (). Observed detection limits may vary between ground waters, depending on the nature of interferences in the sample matrix and the specific instrumentation used.

1.3 This test method is restricted to use by, or under the supervision of, analysts experienced in both the use of liquid chromatography and the interpretation of liquid chromatograms. Each analyst should demonstrate an ability to generate acceptable results with this test method using the procedure described in .

1.4 When this test method is used to analyze unfamiliar samples for any or all of the analytes listed in , analyte identifications should be confirmed by at least one additional qualitative technique.