Navigation Links
Determination of Polar Organophosphorus Pesticides in Aqueous Samples by Direct Injection Using HPLC/MS/MS

A very straightforward method for the analysis of the very polar organophosphorus pesticides (OPs), acephate, methamidophos, omethoate, oxydemeton-methyl, vamidothion, and monocrotophos in water has been developed. Large volume (1 ml) water samples were directly injected onto a RP18 HPLC column with a polar endcapping. The compounds were ionized using APCI and detected on a tandem mass spectrometer operated in multiple reaction-monitoring mode. The detection limits are in the range of 0.01 0.03 μg/l. The method is applicable for analysis of polar OPs in surface, ground, and drinking water. Compared to conventional GC methods, the developed LC/MS procedure is very straightforward, fast, and more reliable.

Introduction

The OPs investigated are thermally labile and/or very polar and therefore less GC-amenable. Moreover, especially acephate, methamidophos, monocrotophos, and omethoate are extremely water soluble and, in contrast to most other pesticides that are quoted in literature as highly polar (e.g. oxamyl, acidic pesticides, dichlorvos, mevinphos, dimethoate), not extractable (after the adequate pH adjustment) using the more common LLE or SPE procedures.

GC-methods

Extraction efficiency of polar OPs using SPE:

MS/MS chromatogram of a surface water sample found positive on acephate. Acephate was detected at a level of 0.2 μg/l. The trace of methamidophos (peak indicated with arrow, approx. 0.03 μg/l) can be expected since methamidophos has been identified as a major metabolite of acephate.

Conclusion

For the very polar OPs included in this work, LC/MS/MS proves to be a more favorable alternative to GC analysis. The method is very straightforward, highly sensitive and selective. After filtration and acidification, water samples are dire ctly injected onto a LC-MS system. By direct injection of 1 ml, the LOD (S/N = 3) varied between 0.01 and 0.03 μg/l depending on the analyte and applied resolution. It may be possible to further lower the LOD by injection of even larger volumes, directly on the analytical column or by (on-line) SPE applying a pre-column packed with the same stationary phase.

Reference

Journal of Chromatography A, 918 (2001)67-78


'"/>

Source:


Page: All 1 2

Related biology technology :

1. Structural Determination of Flavonoids Using MSn
2. Total Cellular Protein Determination Using the DC Protein Assay
3. Simultaneous Determination of Residues of Approximately 100 Pesticides and Metabolites in Fruit and Vegetables by LC/MS/MS
4. Determination of N-nitrosamines in Baby Bottle Rubber Teats by Liquid Chromatography-Atmospheric Pressure Chemical Ionization Mass Spectrometry
5. Determination of the Chloramphenicol residues in milk and milk products using LC/MS/MS
6. A Microtiter-based Assay for the Determination of ID50s of b-lactamase Inhibitors Employing Reporter Substrates Detected at UV or Visible Wavelengths (MaxLine Application Note #20)
7. Determination of Acepromazine and its Major Metabolite in Equine Serum by LC-MS/MS using the Finnigan LCQ Deca XP Plus Ion Trap Mass Spectrometer
8. Receptor Binding Assays using Fluorescence Polarization Detection: the [FP]2TM Characterized Tracers
9. TKXtra DataFile: Homogenous tyrosine kinase detection using High Efficiency Fluorescence Polarization
10. cAMP DataFile: Homogenous Cyclic AMP detection using High Efficiency Fluorescence Polarization
11. Novel Bonding Chemistry Imparts Enhanced Polar Selectivity to TSK-GEL ODS-100V Reversed Phase Columns
Post Your Comments:
*Name:
*Comment:
*Email:


(Date:5/24/2017)... As Ebola resurfaces in the Democratic ... suspected cases now reported, a new analysis of the Ebola ... correlation between the 2014 and 2017 outbreaks of the disease.  ... 2012-13, which preceded the 2014 outbreak. An analysis of the ... counts in 2014-15, which again precedes the current outbreak in ...
(Date:5/23/2017)... , ... May 22, 2017 , ... ... in a row in the Aragon Research Globe™ for Corporate Learning, 2017. , ... industry direction and market demand, and effectively perform against those strategies. NetDimensions’ ranking ...
(Date:5/23/2017)... (PRWEB) , ... May 23, 2017 , ... Bacterial biofilms, ... polymeric molecules, can cause diverse pathologies ranging from food poisoning and catheter infections to ... biofilms is in the tens of billions of dollars per year, there is currently ...
(Date:5/22/2017)... ... 2017 , ... Cancer diagnostics and pathology workflow solution provider ... Association for Pathology Informatics Annual Summit at the Wyndham Grand Hotel ... Diagnostic Cockpit and Consultation Portal, Inspirata will present research it led to help ...
Breaking Biology Technology:
(Date:5/16/2017)... DALLAS , May 16, 2017   ... for health organizations, and MD EMR Systems ... certified development partner for GE, have established a ... Patient Portal product and the GE Centricity™ products, ... Centricity EMR. These new integrations ...
(Date:4/17/2017)... , April 17, 2017 NXT-ID, Inc. ... company, announces the filing of its 2016 Annual Report on Form ... Exchange Commission. ... Form 10-K is available in the Investor Relations section of the ... on the SEC,s website at http://www.sec.gov . 2016 ...
(Date:4/11/2017)... , April 11, 2017 No two ... researchers at the New York University Tandon School ... Engineering have found that partial similarities between prints ... used in mobile phones and other electronic devices ... The vulnerability lies in the fact that ...
Breaking Biology News(10 mins):