The Research Of Methods To Detect Or Identify Swill Oil

As economic and social growing rapidly,the demand for oil is increasing, the result that a large number of restaurant waste oils came into being.Swill oil as one of that have been wantonly collected by a number of lawless elements,after a simple post-processing,then sold at very low prices for restaurants or oil workshop to reuse,or incorporated to qualified oil,confused as real ones,not only disrupted the oil market,but brought great damage also to people's health and safety,further more is a potentially serious security risk to the area of food safety.In order to accurately detect,identify swill oil,control the illegal flow of swill oil,contain the erosion of the food industry by swill oil,prevent the incident swill oil,At the same time as to provide a reasonable and accurate detection means for the regulatory authorities as well as to provide effective law enforcements based on for law enforcement agencies.In this paper,has done a more systematic study to detect or identify swill oil,the methods and the conclusion are as follows:1,Through measuring the water conductivity of the oil sample is a rapid identification method of swill oil and edible oil.At the same time come to the best extraction conditions for measuring the conductivity were as follows:adding the volume of deionized water was 2 times than oil sample and adding the volume of petroleum ether was 2.5 times than oil sample,after ultrasonic oscillated 5min then separated water to measure the conductivity,under these conditions,the determination of the conductivity with good stability and experimental reproducibility,and results showed that the the conductivity and swill oil contents as a better positive correlation,for the reason that measuring the water conductivity also has a good detection of edible oil which mixed against the swill oil.2,Swill oil contains large quantities of aldehydes,ketones which edible oil was non-compliance in the original,these substances in TLC experiments showed as significant tailing phenomenon,therefore,TLC can be used to detect swill oil. Experimental results showed the best chromatography conditions as follow:useing ethyl acetate:petroleum ether=1:4 as mobile phase,using iodine as color reagent useding start up an expansion method.Under these conditions the phenomenon of tailing were apparent and separation were better,mixing of different proportions of swill oil and pure swill oil had obvious tail spots at R_f=0.35.At the same time, came to the minimum detection limit of edible oil which mixed against the swill oil was 5%.3,Through analyzing fatty acid composition among typical of animal fats, typical vegetable oil and swill oil by gas chromatography,the results were as follows:myristic acid is a characteristic of the difference among the three samples. content of myristic acid in swill oil is much higher than typical vegetable oils (content≤0.08%),but significantly lower than the typical animal fats(content was 1.82%),lies between the two,therefore,analyze the fatty acid composition of oil samples,examine whether it contains myristic acid,determine the content of myristic acid,the swill oil can be identified.