传统的农药残留检测为理化检验方法，具有前处理过程繁琐、耗时、复杂等不足，以目前农业上使用较广的毒死蜱作为研究对象，提出了一种有机磷农药残留快速定量检测方法。首先，根据毒死蜱的化学特性，综合考虑比色剂的显色效果以及二次...传统的农药残留检测为理化检验方法，具有前处理过程繁琐、耗时、复杂等不足，以目前农业上使用较广的毒死蜱作为研究对象，提出了一种有机磷农药残留快速定量检测方法。首先，根据毒死蜱的化学特性，综合考虑比色剂的显色效果以及二次污染问题，确定在弱碱性环境下以间苯二酚对毒死蜱进行显色反应的预处理方案；然后，通过分析0.5～400 mg · kg -1之间毒死蜱样品的紫外-可见光光谱数据，确定了显色反应后的特征信息主要集中在365～420 nm之间。接着，以偏最小二乘法构建全谱预测模型，其校正相关系数达到0.9996，预测相关系数达到0.9956，校正标准差RMSEC为2.8147 mg · kg -1，验证标准差RM-SEP为8.0124 mg · kg -1；提取400 nm为中心波段的特征区域构建预测模型，其校正相关系数达到0.9996，预测相关系数达到0.9993，校正标准差RMSEC为2.6546 mg · kg -1，验证标准差RMSEP为3.4655 mg · kg -1。最后，通过分析0.5～16 mg · kg -1之间毒死蜱样品的近红外光谱数据，发现其显色功能团的特征不是很明显，但会引起间苯二酚本身5200 cm -1处吸收峰的变化。实验结果证明了所提出用于快速定量预测有机磷农药残留的方法是有效可行的，该方法通过比色剂的显色加强有机磷农药在全光谱特别是紫外-可见光范围内的信息，为实现农产品农药残留的快速检测提供了一条新途经。展开更多
The statistical system of household assets in US had two categories.which were balance sheet of households and assets ownership by type of household characteristic.Recently,the household asset structure in US presente...The statistical system of household assets in US had two categories.which were balance sheet of households and assets ownership by type of household characteristic.Recently,the household asset structure in US presented the style of low risky and low reserve.The household asset debt rate was 18% and the net asset disposable personal income rate was 54 in 2003There was big gap of net worth between poor and rich households in US.China should establish the statistical system of household assets,which should be well applied in the situation of China.展开更多
文摘传统的农药残留检测为理化检验方法，具有前处理过程繁琐、耗时、复杂等不足，以目前农业上使用较广的毒死蜱作为研究对象，提出了一种有机磷农药残留快速定量检测方法。首先，根据毒死蜱的化学特性，综合考虑比色剂的显色效果以及二次污染问题，确定在弱碱性环境下以间苯二酚对毒死蜱进行显色反应的预处理方案；然后，通过分析0.5～400 mg · kg -1之间毒死蜱样品的紫外-可见光光谱数据，确定了显色反应后的特征信息主要集中在365～420 nm之间。接着，以偏最小二乘法构建全谱预测模型，其校正相关系数达到0.9996，预测相关系数达到0.9956，校正标准差RMSEC为2.8147 mg · kg -1，验证标准差RM-SEP为8.0124 mg · kg -1；提取400 nm为中心波段的特征区域构建预测模型，其校正相关系数达到0.9996，预测相关系数达到0.9993，校正标准差RMSEC为2.6546 mg · kg -1，验证标准差RMSEP为3.4655 mg · kg -1。最后，通过分析0.5～16 mg · kg -1之间毒死蜱样品的近红外光谱数据，发现其显色功能团的特征不是很明显，但会引起间苯二酚本身5200 cm -1处吸收峰的变化。实验结果证明了所提出用于快速定量预测有机磷农药残留的方法是有效可行的，该方法通过比色剂的显色加强有机磷农药在全光谱特别是紫外-可见光范围内的信息，为实现农产品农药残留的快速检测提供了一条新途经。
文摘The statistical system of household assets in US had two categories.which were balance sheet of households and assets ownership by type of household characteristic.Recently,the household asset structure in US presented the style of low risky and low reserve.The household asset debt rate was 18% and the net asset disposable personal income rate was 54 in 2003There was big gap of net worth between poor and rich households in US.China should establish the statistical system of household assets,which should be well applied in the situation of China.
