新型助燃剂金刚砂处理样品的含氟量测定效果评价

目的 筛选新型助燃剂,评价其对样品含氟量测定的效果.方法 采用助燃剂金钢砂和二氧化硅(SiO_2)用于样品的消化处理,采用高温燃烧水解-氟电极法测定样品含氟量.以精密度试验、准确度试验(标准物质对照分析试验、加标回收率试验)及消化方法比较实验评价新型助燃剂的助燃效果.结果 筛选出新型助燃剂金刚砂,即碳化硅(SiC),其耐热、化学性质稳定,对器材无损害.用SiC处理的骨、牙齿、玉米、土豆、土壤、燃煤样品含氟量测定的精密度、准确度良好,变异系数(CV)为0.75%～2.75%;标准物质(煤CRM040、河流泥GSD-6、甘蓝粉)对照分析试验回收率分别为100.5%、100.7%、100.3%;骨、牙齿、小米、辣椒样品加标回收率分别为99.9%、100.2%、100.1%、99.8%.高温燃烧水解法测定样品含氟量的CV、回收率分别为0.76%、100.23%,优于碱融法(5.10%、82.16%)和马弗炉灰化法(4.80%、86.92%).结论 采用SiC处理测定的样品,含氟量测定结果具有良好的精密度和准确度.

Evaluation of a new model combustion improver-carborundum in digestive treatment of fluorine-containing samples

Objective To screen a new combustion improver and evaluate its effect in the determination of the quantity of fluoride in samples. Methods Carborundum (SIC) and silica (SiO_2) screened was applied to the treatment of determining the quantity of the fluoride. The quantity of the fluoride in some samples was determined by F-ion selective electrode method. The treatment effect of the new combustion improver was evaluated by precision test, accuracy test (comparative trials of standard samples, recovery of standard addition test of samples), and comparative test of sample digesting methods. Results New type combustion improver-carborundum, with high thermal stability and steady chemical property, did not damage equipment. The coefficients of variation (CV) reached the range of 0.75% - 2.75%. The recovery rates of the control experiment on reference materials of GSD-6 Belgian River mud, RM: CRM040 Belgian standard coal,and kale powder imperial standard were 100.7%, 100.5% and 100.3%. The recovery rates of standard addition material of bone, teeth, millet and hot pepper were 99.9%, 100.2% ,100.1% ,99.8%. CV and the recovery rates of determining content by the high temperature combustion-hydrolysis/F-ion selective electrode method were 0.76% and 100.23%, better than those of Molten alkali method (5.10%, 82.16%) and Muffle furnace ashing method(4.80%,86.92%). Conclusions The analysis results of all kinds of samples, indicate good precision and accuracy using carborundum as combustion improver,which makes it possible to use high temperature combustion-hydrolysis method in the determination of samples with high-calcium.