Studies On The Degradation Of Carbofuran And The Determination Of Carbofuran Residue In Aquatic Products And Fishery Waters

Carbofuran is a broad-spectrum carbamate used as an insecticide,acaricide and nematocide. It is wildly used in agricultrue because of their service to control insects and other pests. However, due to past abuse of pesticides, carbofuran persists in water and soil and then brings long injuries for aquatic annuals as well as for human health. In this paper, a capillary gas chromatography with nitrogen phosphorus detection method was developed for simultaneous determining the residues of carbofuran in fish muscle and in fishery water; a gas chromatography-mass spectrometric detection (GC-MS) was developed for determining the residue of carbofuran in fishery water; the metabolism of carbofuran in fishery water is also studied.1. A capillary gas chromatography with nitrogen phosphorus detection method was developed for determining the residues of carbofuran in fish muscule. The standard curves were linear in the investigated ranges, 0.1～10.0mg/L of carbofuran. The correlation coefficient r≥0.9989. The recoveries were 82.61%～103.04% at spiking levels 0.1～1.0mg/kg. The relative standard deviations were 2.49%～6.93%. The detection limit of carbofuran was 0.02mg/kg. The method proved to be fast, accurate and simple, also suitable for simultaneous determination of residues of carbofuran in aquatic products.2. A capillary gas chromatography with nitrogen phosphorus detection method was developed for determining the residues of carbofuran in fishery water. The standard curves were linear in the investigated ranges, 0.1～10.0mg/L of carbofuran. The correlation coefficient r≥0.9995. The recoveries were 86.21%～95.97% at spiking levels 1.0～50μg/L. The relative standard deviations were 2.45%～7.24%. The detection limit of carbofuran was 1μg/L. It is suitable for determination of residues of carbofuran in fishery water.3. A capillary gas chromatography-mass spectrometric detection(GC-MS) was developed for determining the residue of carbofuran in fishery water. The sample was extracted with benzene, then ready for determination in SIS mode. The standard curves were linear in the investigated ranges, 0～1000μg/L. The recoveries were 85.21%,98.74% and 94.58%, at spiking levels 0.5μg/L,1.0μg/L and 5.0μg/L, respectively. The relative standard deviation were 6.39%～9.76%. The detection limit of carbofuran was 0.5μg/L. Carbofuran and the metabolism product carbofuran -7-phenol were qualitated and quantitated by their retention time and their character ion m/z 221, 164, 149, 122 and m/z 164, 149, 131, respectively. The results showed that the method is more sensitive, simple, accurate, rapid, particular for the determination of residues of carbofuran in fishery water.4. It was studied that the degradation of carbofuran and the metabolism product carbofuran-7-phenol in fishery water. Carbofuran is instable in alkaline medium and also hydrolyzed in water. Determine carbofuran and carbofuran-7-phenol at different time, in different spiked concentration. The results demonstrated that carbofuran degrade stably in the process of hydrolysis, then bounce in 48h, and degrade to 1% of the prime concentration in 480h. The carbofuran-7-phenol degrade at first and bounce in 24h and then degrade gradually.