Significance and Use
This is a performance based method, and modifications are allowed to improve performance.
Due to the rapid development of newer instrumentation and column chemistries, changes to the analysis described in this standard are allowed as long as better or equivalent performance data result. Any modifications shall be documented and performance data generated. The user of the data generated by this Standard shall be made aware of these changes and given the performance data demonstrating better or equivalent performance.
Organophosphate pesticides affect the nervous system by disrupting the enzyme that regulates acetylcholine, a neurotransmitter. They were developed during the early 19th century, but their effects on insects, which were similar to their effects on humans, were discovered in 1932. Some are poisonous and were used as chemical weapon agents. Organophosphate pesticides are usually not persistent in the environment. ,
This test method is for the analysis of selected organophosphorous based pesticide degradation products.
This method has been investigated for use with various soils.
Scope
1.1 This procedure covers the determination of Diisopropyl Methylphosphonate (DIMP), Ethyl Methylphosphonic Acid (EMPA), Isopropyl Methylphosphonic Acid (IMPA), Methylphosphonic Acid (MPA) and Pinacolyl Methylphosphonic Acid (PMPA), referred to collectively as organophosphonates (OPs) in this test method, in soil. This method is based upon solvent extraction of a soil by pressurized fluid extraction (PFE). The extract is filtered and analyzed by liquid chromatography/tandem mass spectrometry (LC/MS/MS). OPs are qualitatively and quantitatively determined by this method.
1.2 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 The Method Detection Limit (MDL), electrospray ionization (ESI) mode and Reporting Range for the OPs are listed in Table 1.
1.4 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.
TABLE 1 Method Detection Limit and Reporting Range
| Analyte | ESI Mode | MDL (PPB) | Reporting Range (PPB) |
|---|---|---|---|
| Diisopropyl methylphosphonate | Positive | 2.7 | 40-2000 |
| Ethyl methylphosphonic acid | Negative | 2.3 | 40-2000 |
| Ethyl methylphosphonic acid | Positive | 1.3 | 40-2000 |
| Isopropyl methylphosphonic acid | Negative | 5.7 | 40-2000 |
| Isopropyl methylphosphonic acid | Positive | 2.8 | 40-2000 |
| Methylphosphonic acid | Positive | 8.7 | 40-2000 |
| Pinacolyl methylphosphonic acid | Negative | 5.3 | 40-2000 |
