建立了电感耦合等离子体质谱法(ICP-MS)混合模式测定动植物源食品中11种痕量元素的检测方法。样品经微波消解后,采用混合模式测定动植物源食品中As,Hg,Pb,Cd,Cr,Co,Ni,Cu,Zn,Fe,M n 11种元素,内标法定量。结果表明:11种元素的检出限分别...建立了电感耦合等离子体质谱法(ICP-MS)混合模式测定动植物源食品中11种痕量元素的检测方法。样品经微波消解后,采用混合模式测定动植物源食品中As,Hg,Pb,Cd,Cr,Co,Ni,Cu,Zn,Fe,M n 11种元素,内标法定量。结果表明:11种元素的检出限分别在0.005~0.09μg/L之间;线性关系良好,相关系数r≥0.9995;相对标准偏差(RSD)为0.94%~7.2%;回收率在90.7%~103.5%之间;对不同食品类型的对照标准样品GBW10016、GBW10018、GBW10044、GBW10051进行测定,测定结果均在参考值范围。本方法适用于批量动植物源食品中多元素的同时测定。展开更多
This study was aimed at determining the effects of mixed and single cropping agroecosystems on the prevalence of different species of insect pests and coccinellids. It involved six growing crops： maize Zea mays L., b...This study was aimed at determining the effects of mixed and single cropping agroecosystems on the prevalence of different species of insect pests and coccinellids. It involved six growing crops： maize Zea mays L., beans Phaseolus vulgaris L. and cowpeas Vignaunguiculata L. Walp in single and mixed stands and sampling throughout the phenology of the crops. Eight insect pest species were recorded on maize grown alone, while thirty seven insect species were endemic on cowpea mono cropped and were of six orders whereas twenty two insect pest species occurred on beans. The predator population was most abundant in the mixed stands of maize and beans （2.33 predators per 30 aphids） as compared to their occurrence in pure stands of cowpeas （0.85 predators per 30 aphids） as there were numerous aphids on beans at pre-flowering phase that supported a higher population level of coccinellids. Also, predator population was at the peak during the tussling stage of maize as they fed on the pollen grains while aphids on cowpeas co-existed mutualistically with black ants that protected them against predation. The genus Cheilomenes spp. was the most ubiquitous predator with a mean of 4.00 individuals per 30 aphids while Hippodamiavariegata was the least abundant predator species with a mean of 0.92 individuals per 30 aphids in all the agroecosystems as the Cheilomenes spp. had a faster discovery rate, range of perception, effective capture efficiency and a shorter handling time of a prey.展开更多
文摘建立了电感耦合等离子体质谱法(ICP-MS)混合模式测定动植物源食品中11种痕量元素的检测方法。样品经微波消解后,采用混合模式测定动植物源食品中As,Hg,Pb,Cd,Cr,Co,Ni,Cu,Zn,Fe,M n 11种元素,内标法定量。结果表明:11种元素的检出限分别在0.005~0.09μg/L之间;线性关系良好,相关系数r≥0.9995;相对标准偏差(RSD)为0.94%~7.2%;回收率在90.7%~103.5%之间;对不同食品类型的对照标准样品GBW10016、GBW10018、GBW10044、GBW10051进行测定,测定结果均在参考值范围。本方法适用于批量动植物源食品中多元素的同时测定。
文摘This study was aimed at determining the effects of mixed and single cropping agroecosystems on the prevalence of different species of insect pests and coccinellids. It involved six growing crops： maize Zea mays L., beans Phaseolus vulgaris L. and cowpeas Vignaunguiculata L. Walp in single and mixed stands and sampling throughout the phenology of the crops. Eight insect pest species were recorded on maize grown alone, while thirty seven insect species were endemic on cowpea mono cropped and were of six orders whereas twenty two insect pest species occurred on beans. The predator population was most abundant in the mixed stands of maize and beans （2.33 predators per 30 aphids） as compared to their occurrence in pure stands of cowpeas （0.85 predators per 30 aphids） as there were numerous aphids on beans at pre-flowering phase that supported a higher population level of coccinellids. Also, predator population was at the peak during the tussling stage of maize as they fed on the pollen grains while aphids on cowpeas co-existed mutualistically with black ants that protected them against predation. The genus Cheilomenes spp. was the most ubiquitous predator with a mean of 4.00 individuals per 30 aphids while Hippodamiavariegata was the least abundant predator species with a mean of 0.92 individuals per 30 aphids in all the agroecosystems as the Cheilomenes spp. had a faster discovery rate, range of perception, effective capture efficiency and a shorter handling time of a prey.
