[Objective] A method was developed for the determination of 10 pyrethroids pesticide residues in rice by GC-MS-MS. [Method] Pyrethroids were extracted with acetonitrile, followed by a salting-out step with anhydrous m...[Objective] A method was developed for the determination of 10 pyrethroids pesticide residues in rice by GC-MS-MS. [Method] Pyrethroids were extracted with acetonitrile, followed by a salting-out step with anhydrous magnesium sulfate and sodium chloride, cleaned up by florisil solid phase extraction （SPE） cartridge, and determined by multiple reaction monitoring mode. [Result] The method showed good linearity over the range of 0.010-0.500 mg/L for 10 pyrethroid pesticide with correlation coefficients over 0.99. The detection limits were 0.005 -0.010 mg/kg. The method was validated by analyzing samples spiked with 0.05, 0.10, 0.20 mg/kg of 10 pyrethroid pesticides, respectively. The average recoveries in rice ranged from 75.0-115.5%, and the relative standard deviations （RSD） were between 3.9%-6.9%. [Conclusion] The method is easy, accurate and reliable, which can meet the requirement for the simultaneous determination and confirmation of pyrethroid pesticide residues in rice.展开更多
Pesticide residues in fruit and vegetables have become a major concern associated with chemical food safety issues. Translocation of pesticides in tomato, mango and pineapple fruits in locally produced samples was inv...Pesticide residues in fruit and vegetables have become a major concern associated with chemical food safety issues. Translocation of pesticides in tomato, mango and pineapple fruits in locally produced samples was investigated using gas chromatography/mass spectrophotometer （GC/MS） procedures. Samples were fractionated with respect to distance from the skin to the core and prepared for analysis. Results showed that organochlorine, organophosphate and synthetic pyrethroid residues were translocated in all fruit samples analyzed. With respect to tomato fractions, the peels retained more residues compared to the pulp and the central core. In the chemical species, organochlorines were retained more in the peels of tomato than the other fractions of the fruit. More organophosphate and organochlorine residues were detected in pineapple peels compared to the pulp. Synthetic pyrethroid residues were evenly distributed in the pineapple fruit. In mangoes, the pulp retained more chemical residues than other fractions of the fruit. More organochlorine residues were retained in the pulp of mango than in the other fractions of the fruit. Synthetic pyrethroid residues were evenly distributed throughout the mango fruit. All the chemical species identified were translocatable across the fractional parts of all the fruits. There were significant differences in translocation and residue accumulation of pesticides among the fractional parts of all samples.展开更多
A pyrethroid insecticide-degrading bacterium, strain HS-24, was isolated from an offshore seawater environment. The strain, which can degrade cypermethrin （CYP） and deltamethrin （DEL）, was identified as Methylopha...A pyrethroid insecticide-degrading bacterium, strain HS-24, was isolated from an offshore seawater environment. The strain, which can degrade cypermethrin （CYP） and deltamethrin （DEL）, was identified as Methylophaga sp. The optimal culture and degradation conditions for CYP and DEL by strain HS-24 is pH 7 at 28℃. Under optimum culture conditions, strain HS-24 exhibited a broad degradation concentration range of 100, 200, 400, 600, and 800 mg/L for CYP and DEL. The metabolic intermediates were analyzed by NMR, which provided strong evidence that CYP and DEL removal occurred mainly because of a biological process. The toxicity of the degradation products of strain HS-24 was studied simultaneously by measuring the light output of the luminescence bacterium. This demonstrated that the biodegradation ability of strain HS-24 significantly decreased the toxicity of CYP- and DEL-contaminated aquaculture seawater. Finally, the findings of this paper indicate that strain HS-24 is thus revealed as a biological agent for the remediation of marine aquatic environments.展开更多
Leafhopper Cicadulina bipunctata is represented the main insect as a pathogen for phytoplasma disease occurring by insect-transmitted plant viruses in date palm orchards. Therefore, it is important to investigate the ...Leafhopper Cicadulina bipunctata is represented the main insect as a pathogen for phytoplasma disease occurring by insect-transmitted plant viruses in date palm orchards. Therefore, it is important to investigate the potential effect of some insecticides against such insect. The adults of leafhopper C. bipunctata were collected from date palm orchards in Alhasa, Eastern province, Saudi Arabia. Three insecticides from different classes--beta-cyfluthrin （pyrethroids）, imidacloprid （neonicotinoids） and abamectin （natural compounds）--have been evaluated in vivo against adults C. bipunctata. This stage was exposed to residual film of various concentrations of each insecticide on transparent plastic cups using a Potter precision laboratory spray tower. Bioassay test showed that both beta-cyfluthrin and imidacloprid caused 100% mortality by 500 ppm at 24 h after treatment, whereas abamectin gave the same mortality by 50 ppm at the same time. Toxicity values revealed that abameetin was the most potent insecticide compared with beta-cyfluthrin and imidacloprid, where the lethal concentrations LC50 and LC95 were 24.58 ppm and 116.73 ppm at 3 h after treatment, respectively. Therefore, abamectin can be a possible candidate to be applied on date palm or ground grass by the Ministry of Agriculture after successful field experiments.展开更多
Repeated applications of bordeaux mixture （a blend of copper sulfate and calcium hydroxide） and pyrethroid insecticides （Pys） have led to elevated copper （Cu） and Pys concentrations in vineyard surface soils. To...Repeated applications of bordeaux mixture （a blend of copper sulfate and calcium hydroxide） and pyrethroid insecticides （Pys） have led to elevated copper （Cu） and Pys concentrations in vineyard surface soils. To understand the potential influence of Cu on the fate of Pys in the soil environment, we selected two Pys, cypermethrin （CPM） and lambda-cyhalothrin （A-CHT）, and two typical Chinese vineyard soils, Haplic Acrisol and Luvic Phaeozem, as experimental samples. The dissipation experiment was conducted at room temperature in the dark, and the transport of both Pys through the soils was investigated using soil thin-layer chromatography. The results showed that the transport of Pys in both soils increased as the Cu2＋ concentration increased from 0 to 100 mg L-1, and Pys were more transportable in Haplic Acrisol （HA） than in Luvic Phaeozem （LP） under the same experimental conditions. For CPM, only 100 mg L-1 of Cu2＋ significantly （P 〈 0.05） increased Pys transport through both soils relative to water. Lambda-CHT was significantly （P〈0.05） transported through HA by all the Cu2＋ concentrations compared to water, and all but the 1 mg L-1 of Cu2＋ significantly （P 〈 0.05） increased the transport of A-CHT through LP relative to water. However, the dissipation rates of CPM and λ-CHT decreased with the addition of Cu to soils. Our findings suggest that the risk of groundwater contamination by Pys increases in the soils with elevated Cu concentrations.展开更多
文摘[Objective] A method was developed for the determination of 10 pyrethroids pesticide residues in rice by GC-MS-MS. [Method] Pyrethroids were extracted with acetonitrile, followed by a salting-out step with anhydrous magnesium sulfate and sodium chloride, cleaned up by florisil solid phase extraction （SPE） cartridge, and determined by multiple reaction monitoring mode. [Result] The method showed good linearity over the range of 0.010-0.500 mg/L for 10 pyrethroid pesticide with correlation coefficients over 0.99. The detection limits were 0.005 -0.010 mg/kg. The method was validated by analyzing samples spiked with 0.05, 0.10, 0.20 mg/kg of 10 pyrethroid pesticides, respectively. The average recoveries in rice ranged from 75.0-115.5%, and the relative standard deviations （RSD） were between 3.9%-6.9%. [Conclusion] The method is easy, accurate and reliable, which can meet the requirement for the simultaneous determination and confirmation of pyrethroid pesticide residues in rice.
文摘Pesticide residues in fruit and vegetables have become a major concern associated with chemical food safety issues. Translocation of pesticides in tomato, mango and pineapple fruits in locally produced samples was investigated using gas chromatography/mass spectrophotometer （GC/MS） procedures. Samples were fractionated with respect to distance from the skin to the core and prepared for analysis. Results showed that organochlorine, organophosphate and synthetic pyrethroid residues were translocated in all fruit samples analyzed. With respect to tomato fractions, the peels retained more residues compared to the pulp and the central core. In the chemical species, organochlorines were retained more in the peels of tomato than the other fractions of the fruit. More organophosphate and organochlorine residues were detected in pineapple peels compared to the pulp. Synthetic pyrethroid residues were evenly distributed in the pineapple fruit. In mangoes, the pulp retained more chemical residues than other fractions of the fruit. More organochlorine residues were retained in the pulp of mango than in the other fractions of the fruit. Synthetic pyrethroid residues were evenly distributed throughout the mango fruit. All the chemical species identified were translocatable across the fractional parts of all the fruits. There were significant differences in translocation and residue accumulation of pesticides among the fractional parts of all samples.
基金Supported by the Social Development Fund of Science and Technology Department of Zhejiang Province(No.2013C33091)the Scientific Research Fund of Ningbo University(Nos.xkl11D2098,xkl11091)+1 种基金the National Natural Science Foundation of China(No.31001139)the K.C.Wong Magna Fund of Ningbo University
文摘A pyrethroid insecticide-degrading bacterium, strain HS-24, was isolated from an offshore seawater environment. The strain, which can degrade cypermethrin （CYP） and deltamethrin （DEL）, was identified as Methylophaga sp. The optimal culture and degradation conditions for CYP and DEL by strain HS-24 is pH 7 at 28℃. Under optimum culture conditions, strain HS-24 exhibited a broad degradation concentration range of 100, 200, 400, 600, and 800 mg/L for CYP and DEL. The metabolic intermediates were analyzed by NMR, which provided strong evidence that CYP and DEL removal occurred mainly because of a biological process. The toxicity of the degradation products of strain HS-24 was studied simultaneously by measuring the light output of the luminescence bacterium. This demonstrated that the biodegradation ability of strain HS-24 significantly decreased the toxicity of CYP- and DEL-contaminated aquaculture seawater. Finally, the findings of this paper indicate that strain HS-24 is thus revealed as a biological agent for the remediation of marine aquatic environments.
文摘Leafhopper Cicadulina bipunctata is represented the main insect as a pathogen for phytoplasma disease occurring by insect-transmitted plant viruses in date palm orchards. Therefore, it is important to investigate the potential effect of some insecticides against such insect. The adults of leafhopper C. bipunctata were collected from date palm orchards in Alhasa, Eastern province, Saudi Arabia. Three insecticides from different classes--beta-cyfluthrin （pyrethroids）, imidacloprid （neonicotinoids） and abamectin （natural compounds）--have been evaluated in vivo against adults C. bipunctata. This stage was exposed to residual film of various concentrations of each insecticide on transparent plastic cups using a Potter precision laboratory spray tower. Bioassay test showed that both beta-cyfluthrin and imidacloprid caused 100% mortality by 500 ppm at 24 h after treatment, whereas abamectin gave the same mortality by 50 ppm at the same time. Toxicity values revealed that abameetin was the most potent insecticide compared with beta-cyfluthrin and imidacloprid, where the lethal concentrations LC50 and LC95 were 24.58 ppm and 116.73 ppm at 3 h after treatment, respectively. Therefore, abamectin can be a possible candidate to be applied on date palm or ground grass by the Ministry of Agriculture after successful field experiments.
基金Supported by the China Postdoctoral Science Foundation (No. 20090461068)the Jiangsu Provincial Planned Projects for Postdoctoral Research Funds, China (No. 1001021B)+1 种基金the Scientific Research Foundation for Talented Scholars of Jiangsu University, China(No. 10JDG039)the Open Fund of State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences (No. Y052010043)
文摘Repeated applications of bordeaux mixture （a blend of copper sulfate and calcium hydroxide） and pyrethroid insecticides （Pys） have led to elevated copper （Cu） and Pys concentrations in vineyard surface soils. To understand the potential influence of Cu on the fate of Pys in the soil environment, we selected two Pys, cypermethrin （CPM） and lambda-cyhalothrin （A-CHT）, and two typical Chinese vineyard soils, Haplic Acrisol and Luvic Phaeozem, as experimental samples. The dissipation experiment was conducted at room temperature in the dark, and the transport of both Pys through the soils was investigated using soil thin-layer chromatography. The results showed that the transport of Pys in both soils increased as the Cu2＋ concentration increased from 0 to 100 mg L-1, and Pys were more transportable in Haplic Acrisol （HA） than in Luvic Phaeozem （LP） under the same experimental conditions. For CPM, only 100 mg L-1 of Cu2＋ significantly （P 〈 0.05） increased Pys transport through both soils relative to water. Lambda-CHT was significantly （P〈0.05） transported through HA by all the Cu2＋ concentrations compared to water, and all but the 1 mg L-1 of Cu2＋ significantly （P 〈 0.05） increased the transport of A-CHT through LP relative to water. However, the dissipation rates of CPM and λ-CHT decreased with the addition of Cu to soils. Our findings suggest that the risk of groundwater contamination by Pys increases in the soils with elevated Cu concentrations.
