A simple, convenient and on-site determination method and the corresponding handheld analyzer for monitoring toxicity of organophosphates and carbamates in vegetables were developed based on enzyme catalytic dynamic p...A simple, convenient and on-site determination method and the corresponding handheld analyzer for monitoring toxicity of organophosphates and carbamates in vegetables were developed based on enzyme catalytic dynamic photometry. Variousexperimental parameters were studied and optimized. The toxicity level can be judged according to the enzyme inhibition rate directly displayed on the analyzer. The method is rapid, with an average analysis time of 6-8 min for per sample. It is of practicality and great value, and can effectively be applied for monitoring the toxicity of pesticides, such as organophosphates and carbamates, commonly used for vegetables.展开更多
The indigo carmine was reduced by using cheap,easily attainable and non poisonous reagents. Therefore, a special reagent was developed to measure the concentration of dissolved oxygen in water in situ . The molar abso...The indigo carmine was reduced by using cheap,easily attainable and non poisonous reagents. Therefore, a special reagent was developed to measure the concentration of dissolved oxygen in water in situ . The molar absorption coefficient of the method is 1 35×10 4, and its dynamic linear range is 0-27 mg/L linearity coefficient of 0 997. The most oxidizing species, such as Cl 2, ClO -, Cu 2+ , Fe 3+ , V 5+ , and As(Ⅴ), do not interfere the determination. It takes no more than 1 min to analyze one sample. The method was applied to determining some practical samples and all the results obtained were satisfactory.展开更多
提出了一种用于现场测定水发食品中甲醛含量的样品快速前处理新方法,采用乙酸锌和亚铁氰化钾沉淀样品中的蛋白质和脂肪,在弱酸性介质和沸水浴条件下提取了样品中的甲醛,并与乙酰丙酮立即发生显色反应.研究了不同样品前处理方法对甲醛提...提出了一种用于现场测定水发食品中甲醛含量的样品快速前处理新方法,采用乙酸锌和亚铁氰化钾沉淀样品中的蛋白质和脂肪,在弱酸性介质和沸水浴条件下提取了样品中的甲醛,并与乙酰丙酮立即发生显色反应.研究了不同样品前处理方法对甲醛提取和测定的影响,探讨了水发食品中的甲醛本底值及其是否被人为添加甲醛的判断标准.此方法的特点是样品前处理与显色反应同时进行,在10 m in内即可完成对水发食品中甲醛含量的定量测定.展开更多
文摘A simple, convenient and on-site determination method and the corresponding handheld analyzer for monitoring toxicity of organophosphates and carbamates in vegetables were developed based on enzyme catalytic dynamic photometry. Variousexperimental parameters were studied and optimized. The toxicity level can be judged according to the enzyme inhibition rate directly displayed on the analyzer. The method is rapid, with an average analysis time of 6-8 min for per sample. It is of practicality and great value, and can effectively be applied for monitoring the toxicity of pesticides, such as organophosphates and carbamates, commonly used for vegetables.
文摘The indigo carmine was reduced by using cheap,easily attainable and non poisonous reagents. Therefore, a special reagent was developed to measure the concentration of dissolved oxygen in water in situ . The molar absorption coefficient of the method is 1 35×10 4, and its dynamic linear range is 0-27 mg/L linearity coefficient of 0 997. The most oxidizing species, such as Cl 2, ClO -, Cu 2+ , Fe 3+ , V 5+ , and As(Ⅴ), do not interfere the determination. It takes no more than 1 min to analyze one sample. The method was applied to determining some practical samples and all the results obtained were satisfactory.
文摘提出了一种用于现场测定水发食品中甲醛含量的样品快速前处理新方法,采用乙酸锌和亚铁氰化钾沉淀样品中的蛋白质和脂肪,在弱酸性介质和沸水浴条件下提取了样品中的甲醛,并与乙酰丙酮立即发生显色反应.研究了不同样品前处理方法对甲醛提取和测定的影响,探讨了水发食品中的甲醛本底值及其是否被人为添加甲醛的判断标准.此方法的特点是样品前处理与显色反应同时进行,在10 m in内即可完成对水发食品中甲醛含量的定量测定.