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:10/9/2017)... ... October 09, 2017 , ... The Giving Tree ... products targeting the needs of consumers who are incorporating medical marijuana into their ... Phoenix, Arizona. , As operators of two successful Valley dispensaries, The Giving Tree’s ...
(Date:10/7/2017)... Phoenix, Arizona (PRWEB) , ... ... ... than 15 years’ experience providing advanced instruments and applications consulting for microscopy ... the in-house expertise in application consulting, Nanoscience Analytical offers a broad range ...
(Date:10/7/2017)... Mass. , Oct. 6, 2017  The ... work of three scientists, Jacques Dubochet, Joachim ... breakthrough developments in cryo-electron microscopy (cryo-EM) ... technology within the structural biology community. The winners ... Scientists can now routinely produce highly resolved, three-dimensional ...
(Date:10/6/2017)... ... October 06, 2017 , ... ... discussion and webinar on INSIGhT, the first-ever adaptive clinical trial for glioblastoma (GBM). ... Institute. The event is free and open to the public, but registration is ...
Breaking Biology Technology:
(Date:4/13/2017)... SANTA MONICA, Calif. , April 13, 2017 /PRNewswire/ ... New York will feature emerging and ... Innovation Summits. Both Innovation Summits will run alongside the ... variety of speaker sessions, panels and demonstrations focused on ... east coast,s largest advanced design and manufacturing event will ...
(Date:4/11/2017)... April 11, 2017 No two people ... at the New York University Tandon School of ... have found that partial similarities between prints are ... in mobile phones and other electronic devices can ... The vulnerability lies in the fact that fingerprint-based ...
(Date:4/5/2017)... NEW YORK , April 5, 2017 ... security, is announcing that the server component of the ... is known for providing the end-to-end security architecture that ... customers. HYPR has already secured over 15 ... system makers including manufacturers of connected home product suites ...
Breaking Biology News(10 mins):