可见分光光度法评价食品机械用润滑油的润滑品质

Visible Spectrophotometer Method to Evaluate Lubrication Quality of Food Mechanical Lubricating Oil

食品机械润滑油的润滑性能直接影响机械的磨损程度,进而影响机械的使用寿命。而机械齿轮上的铁元素又是磨损过程中容易剥落的,测定模拟使用后的润滑油中铁元素的磨损量,比较其润滑品质。通过采用分光光度法研究铁含量的最佳试验条件:最大吸收波长为512 nm,10%盐酸羟胺溶液2.50 m L,HAc-Na Ac缓冲溶液(pH 4.7),0.15%邻菲罗啉溶液4.00 m L,显色时间20 min。线性范围为0~2.0μg/m L,符合朗波比尔定律,相关系数r=0.999 4,摩尔吸光系数为1.5×104 L·mol^(-1)·cm^(-1)。对样品分析表明:相对标准偏差分别为0.6%,4.7%,4.3%和3.2%,平均加标回收率97.3%~101.3%,符合国标要求。以该方法清楚得出润滑油的铁磨损量变化趋势,相比得出KLUBER oil4 UH1^(-1)5润滑品质最佳,而大豆植物油润滑品质不佳。

The lubrication performance of the lubricating oil had a direct effect on the machine and the life of machinery, and it was the main index of the oil deterioration. According to the simulation process, content of iron in lubricating oil was determined to compare the quality of lubricating oil. The content of iron was determined by spectrophotometry, the best experimental conditions were as followings： the maximum absorption of the complex was at 512 nm, 10% hydroxylamine hydrochloride solution was 2.50 mL, HAc-NaAc buffer solution （pH 4.7）, 0.15% phenanthroline solution was 4.00 mL, and the time was 20 min. Under the optimum conditions, beers law was obeyed in the range of 0 to 2.0 ~tg/mL of Fe with the correlative coefficient of 0.999 4, and the apparent molar absorption absorptivity of the complex was 1.5× 104 L.moll.cm-1. Different oil samples were analyzed after friction; The relative standard deviations were 0.6%, 4.7%, 4.3% and 3.2%. The average recoveries were 97.3%- 101.3%, complied with national standards. This method could clearly get the change trend of the quantity of the lubricating oil, oil 4 UH 1-15 KLUBER lubricant quality was the best and the edible soybean oil lubrication quality was not good.