磷钼蓝分光光度法测定生物柴油中微量磷

Spectrophotometric Determination of Microamounts of Phosphorus in Biodiesel Fuels by Phospho-Molybdenumblue

通过实验认为钼蓝分光光度法适合于生物柴油中微量磷含量的测定。优化了实验条件,用直接定容取代定容后再分取,使样品的用量减少至原来的1/5,样品炭化和灰化等处理时间大大缩短,使整个分析时间缩短约1 5h。用KOH为催化剂,以大豆油、菜籽油、棉籽油、玉米油、花生油和麻油为原料合成了6种生物柴油。用钼蓝分光光度法测定了它们的磷含量,结果表明当6种植物油采用碱催化制成生物柴油后磷含量显著降低,都小于5mg/kg,能满足德国生物柴油中磷含量小于10mg/kg的标准要求。

It has been proved that the phospho-molybdenumblue photometry can be applied for the determination of phosphorus in biodiesel fuels with satisfactory results.The determinating conditions were optimized.In the new analytical method,the sample size is only 1/5 of the previous one.The sample handling time such as carbonization and ashing was shortened greatly.So the analysis time was shortened about 1.5h.The pure biodiesel fuels of six edible plant oils,which are rapeseed oil,peanut oil,corn oil,cottonseed oil,sesame oil and soyabean oil,have been made by means of base catalysis and transesterification.The phosphorus content in 6 biodiesel fuels,all less than 5mg/kg,has been determinated by phospho-molybdenumblue photometry,accords with the specification of Germany biodiesel fuel and is much lower than that in its plant oil when the biodiesel fuel was made from its plant oil by base catalysis.