Identification of biodegradation products of methyl parathion in aqueous environment by high performance liquid chromatography/mass spectrometry with time-of-flight mass spectrometry
Lee, Frank S. C.
- 化学化工－已发表论文 
The biodegradation of the organophosphorus insecticide methyl parathion, in aqueous suspensions by bacteria L-10 (Shewanella sp.) isolated from river sediment has been studied. The biodegradation process was found to be highly efficient, with the formation of several intermediates that were identified using high performance liquid chromatography/mass spectrometry/diode array detection (HPLC/MS/DAD) and electrospray-time of flight mass spectrometry (TOF-MS). Unlike photocatalytic degradation of methyl parathion, from which the main degradation intermediates include primarily methyl paraoxon and 4-nitrophenol, the degradation products from biodegradation are more diverse because of the complexity of biodegradation processes. The analytical method used in the study can be summarized as the following. The analytical column was a Alltech C, reversed-phase column (4.6 mm x 150 mm, 5 mu m). The diode array detector was set at the wavelength from 190 to 400 nm. Gradient elution was used in HPLC runs. The gradients were formed by varying the proportion of water (A) and acetonitrile ( B), each containing 0.1% (V/V) ammonium formate. The elution systems were that: 0-5 min, 10% of B; 5-20 min, 10%-50% B. The flow rate employed was 0.8 mL/min throughout the run. MS data for parathion-methyl and its degradation products with pasitive ion (PI) ESI detection was acquired by scanning over the m/z ranges of 10-1000. Data were processed using Analyst QS software from Agilent.