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紫外分光光度法测定面粉中的过氧化苯甲酰 总被引:5,自引:0,他引:5
本文基于在酸性条件下,过氧化苯甲酰(BPO)能把Fe2 氧化成Fe3 ,再与邻菲罗啉发生褪色反应,建立了紫外分光光度法测定面粉中过氧化苯甲酰的方法.测定过氧化苯甲酰线性范围为1.0 ×10-7g/mL-3.2×10-6g/mL和3.2 ×10-6g/mL~2.4×10-5g/mL,检出限6.0×10~g/mL,对8.0 ×10-7g/mL过氧化苯甲酰连续11次测定的相对标准偏差RSD为4.2%,已用于面粉中过氧化苯甲酰的测定. 相似文献
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本文采用紫外分光光度法测定水中硝酸盐氮的含量,通过大量实验,即对硝酸盐氮的吸收曲线测定,酸度干扰排除及回收率,精确度验证,并与二磺酸酚法进行比较,本文认为紫外法测定水中硝酸盐氮操作简便、快速、灵敏. 相似文献
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本文介绍了紫外分光光度法测定水中COD的测量原理及发展趋势,紫外分光光度法测定水中COD具有成本低、测量时间短、无污染等优点,已经得到了广泛的应用。 相似文献
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目的:建立紫外分光光度法测定刺五加口服液中总黄酮含量;方法:以芦丁为对照品,于360nm波长处测定吸收度;结果:在5μg/ml~25μg/ml范围内芦丁的浓度与吸光度呈现良好的线性关系(r=0.9998,n=5);结论:用本法测定刺五加口服液中总黄酮含量操作简便,灵敏度高,重现性好,方法可行。 相似文献
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文章首先介绍了实验原理和需要使用的仪器和试剂,然后分析了测定实验的方法以及步骤,并对实验的精度进行了验证,在确保实验精度的前提下得出了实验结果。 相似文献
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通过对影响分光光度计测量准确性的因素进行分析,认为波长准确度是其中的主要因素。对检定用波长标准进行特性研究,确定各种标准器的用途;对波长误差的构成原理进行分析,确定波长误差的调整方法;综合对检定波长产生误差的相关方面进行论述,全面提出了控制波长误差的具体方法,为控制影响分光光度计测量准确度的波长误差提出了一套解决方案。 相似文献
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本文建立了一种梯度升压微波消解样品,氢化物发生双道原子荧光光谱法同时测定蔬菜样品中汞、砷的方法。在优化实验条件下,蔬菜样品中Hg、As回收率分别为98.9%-109.3%和91.1%-96.1%;检出限分别为0.0094μg/L、0.0331μg/L。并对其相讨标准偏差(RSD)、精密度和准确度进行了评估,结果表明该方法用于蔬菜中Hg、As的同时测定是可行的。 相似文献
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Heavy metal contamination in soils and vegetables near an e-waste processing site, South China 总被引:15,自引:0,他引:15
Environmental pollution due to uncontrolled e-waste recycling activities has been reported in a number of locations of China. In the present study, metal pollution to the surrounding environment from a primitive e-waste processing facility was investigated. Soils at sites where e-waste is burned in the open air, those of surrounding paddy fields and vegetable gardens, as well as common vegetable samples were collected and analyzed for heavy metals. The results showed that the soils of former incineration sites had the highest concentrations of Cd, Cu, Pb, and Zn with mean values of 17.1, 11,140, 4500, and 3690 mg kg(-1), respectively. The soils of nearby paddy fields and vegetable gardens also had relatively high concentrations of Cd and Cu. In the edible tissues of vegetables, the concentrations of Cd and Pb in most samples exceeded the maximum level permitted for food in China. Sequential leaching tests revealed that the Cu, Pb, and Zn were predominantly associated with the residual fraction, followed by the carbonate/specifically adsorbed phases with the exception of Cd, which was mainly in the extractable form in paddy fields and vegetable soils. The data showed that uncontrolled e-waste processing operations caused serious pollution to local soils and vegetables. The cleaning up of former incineration sites should be a priority in any future remediation program. 相似文献