目的建立测定艾司唑仑原料中基因毒性杂质甲醛的柱前衍生高效液相色谱方法,考察国内4家企业艾司唑仑原料中甲醛含量水平。方法色谱柱为CAPCELL PAK C8柱,流动相为水-乙腈(60:40),流速为1.0 mL/min,检测波长为360 nm,柱温为30℃,进样量...目的建立测定艾司唑仑原料中基因毒性杂质甲醛的柱前衍生高效液相色谱方法,考察国内4家企业艾司唑仑原料中甲醛含量水平。方法色谱柱为CAPCELL PAK C8柱,流动相为水-乙腈(60:40),流速为1.0 mL/min,检测波长为360 nm,柱温为30℃,进样量为10μL。结果甲醛2,4-二硝基苯腙在浓度0.05~1μg/mL范围内与峰面积线性关系良好(r=0.9998);检测限和定量限分别为6和20μg/g;进样精密度和重复性试验的RSD分别为0.2%和1.4%(n=6);平均加样回收率为101.8%,RSD为0.8%(n=6)。1家企业的2批原料中甲醛含量远超过控制阈值,另外5批原料中甲醛含量均小于定量限。结论建立的甲醛测定方法准确度高,灵敏度强。建议甲醛含量超过控制阈值的生产企业制定合理的控制策略。展开更多
Improving the yield of maize grain per unit area is needed to meet the growing demand for it in China, where the availability of fertile land is very limited.Modified fertilization management and planting density are ...Improving the yield of maize grain per unit area is needed to meet the growing demand for it in China, where the availability of fertile land is very limited.Modified fertilization management and planting density are efficient methods for increasing crop yield.Field experiments were designed to investigate the influence of modified fertilization management and planting density on grain yield and nitrogen use efficiency of the popular maize variety Zhengdan 958, in four treatments including local farmer＇s practice（FP）, high-yielding and high efficiency cultivation（HH）, super high-yielding cultivation（SH）, and the control（CK）.Trials were conducted in three locations of the Huang-Huai-Hai Plain in northern China.Compared with FP, SH was clearly able to promote N absorption and dry matter accumulation in post-anthesis, and achieve high yield and N use efficiency by increasing planting density and postponing the supplementary application of fertilizers.However, with an increase in planting density, the demand of N increased along with grain yield.Due to the input of too much N fertilizer, the efficiency of N use in SH was low.Applying less total N, ameliorating cultivation and cropping management practices should be considered as priority strategies to augment production potential and finally achieve synchronization between high yield and high N efficiency in fertile soils.However, in situations where soil fertility is low, achieving high yield and high N use efficiency in maize will likely depend on increased planting density and appropriate application of supplementary fertilizers postpone to the grain-filling stage.展开更多
文摘目的建立测定艾司唑仑原料中基因毒性杂质甲醛的柱前衍生高效液相色谱方法,考察国内4家企业艾司唑仑原料中甲醛含量水平。方法色谱柱为CAPCELL PAK C8柱,流动相为水-乙腈(60:40),流速为1.0 mL/min,检测波长为360 nm,柱温为30℃,进样量为10μL。结果甲醛2,4-二硝基苯腙在浓度0.05~1μg/mL范围内与峰面积线性关系良好(r=0.9998);检测限和定量限分别为6和20μg/g;进样精密度和重复性试验的RSD分别为0.2%和1.4%(n=6);平均加样回收率为101.8%,RSD为0.8%(n=6)。1家企业的2批原料中甲醛含量远超过控制阈值,另外5批原料中甲醛含量均小于定量限。结论建立的甲醛测定方法准确度高,灵敏度强。建议甲醛含量超过控制阈值的生产企业制定合理的控制策略。
基金supported by grants from the National Natural Science Foundation of China(31371576,31071358,31301274)the European Union’s Seventh Framework Programme(NUE-CROPS 222645)+1 种基金the National Key Technology Support Program of China(2011BAD16B14,2012BAD04B05-2)the Special Fund for Agro-Scientific Research in the Public Interest of China(HY12031100,HY1203096)
文摘Improving the yield of maize grain per unit area is needed to meet the growing demand for it in China, where the availability of fertile land is very limited.Modified fertilization management and planting density are efficient methods for increasing crop yield.Field experiments were designed to investigate the influence of modified fertilization management and planting density on grain yield and nitrogen use efficiency of the popular maize variety Zhengdan 958, in four treatments including local farmer＇s practice（FP）, high-yielding and high efficiency cultivation（HH）, super high-yielding cultivation（SH）, and the control（CK）.Trials were conducted in three locations of the Huang-Huai-Hai Plain in northern China.Compared with FP, SH was clearly able to promote N absorption and dry matter accumulation in post-anthesis, and achieve high yield and N use efficiency by increasing planting density and postponing the supplementary application of fertilizers.However, with an increase in planting density, the demand of N increased along with grain yield.Due to the input of too much N fertilizer, the efficiency of N use in SH was low.Applying less total N, ameliorating cultivation and cropping management practices should be considered as priority strategies to augment production potential and finally achieve synchronization between high yield and high N efficiency in fertile soils.However, in situations where soil fertility is low, achieving high yield and high N use efficiency in maize will likely depend on increased planting density and appropriate application of supplementary fertilizers postpone to the grain-filling stage.
