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Reuse of waste oil in cooking has been the social concern for long time, but until now there is no reliable method to identify the gutter oil.In this work, based on the generation of long-chain aliphatic aldehydes in the refinement of gutter oil, gutter oil and adulterate cooking oil were identified by determining hexanal, heptanal, octanal, nonanal and decanal in oil sample with high perfomance liquid chromatography (HPLC) method using O-(3-(9H-carbazol-9-yl)propyl)hydroxylamine as the fluorescent derivative reagent.At first, 10 μL of oil sample was dissolved in 200 μL of isopropanol, then reacted with O-(3-(9H-carbazol-9-yl)propyl)hydroxylamine to form the stable derivatives, extracted with acetonitrile and injected into HPLC for analysis.The derivatives were separated on a C18 column within 15 min with ACN-H2O (90∶10, V/V) as mobile phase.The fluorescence detector was set at λex/λem=292 nm/348 nm.The linear range of 5 kinds of long-chain aliphatic aldehydes was 0.01-1.00 μmol/L with limit of detection (LOD, S/N=3) of 0.05-0.10 nmol/L, and the spiked recoveries were 95.6%-101.4%.The results showed that the edible oils obtained from supermarket almost had no hexanal, heptanal, octanal, nonanal, decanal, but these aldehydes increased significantly in gutter oil.Thus the 5 kinds of long-chain aldehydes could be used as the indictor of gutter oil.Taking the advantage of good specificity, higher sensitivity, good accuracy and simplicity, the method was suitable for the rapid identification of gutter oil.
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Objective To determine the effects of gutter oil on liver function,renal function and serum lipid metabolism in mice.Methods A total of 72 mice were averagely divided into 6 groups.Mice were gavaged with different dosages (5 μL/g,1 0 μL/g and 20 μL/g)of gutter oil or cooking oil every other day for continuing 8 weeks.The indexes of liver, kidney and serum lipid parameters were assayed.Results The moisture,acid value and peroxide value of the gutter oil exceeded the national standard.After continuing 8 weeks'intake of oils,alanine aminotransferase (ALT)of gutter oil group with a dosage of 5 μL/g,as well as aspartate aminotransferase (AST)of gutter oil group with a dosage of 1 0 μL/g significantly increased (P <0.05),compared with the cooking oil group.Serum creatinine (Scr)of the gutter oil groups with 3 dosages significantly increased compared with the control groups (P <0.05 ).Meanwhile,blood urea nitrogen (BUN)of gutter oil groups with a dosage of 5 μL/g and 1 0 μL/g were also significantly increased respectively(P <0.05). However,no significant differences were observed in triglyceride (TG)and total cholesterol (TC)among the groups. Conclusion Eight weeks'intake of gutter oil could cause the damage to liver and renal functions.
RESUMEN
A special solid phase micro extraction ( SPME ) fibre was successfully attained by coating with a special adsorptive material on a porous stainless steel support. And the porous stainless steel support was prepared by electrochemical corrosion for the first time. The optimized erosion condition in this research was as follows: the current intensity of 30 mA, the stainless steel was etched in 2 mol/L hydrochloride solution for 1 min, then sonicated for 3 min; these procedures repeated 5 times. Meanwhile, the treated fiber coated 35 times in the sorbent solution with concentration of 5% ( m/V) in dichloromethane. The SPME fibre was applied to the analysis of gutter oil samples, and the performance of the SPME fibre for the headspace solid phase micro extraction of the exogenous impurities in gutter oil was specific, durable, stable and low-cost. The four detected trace level characteristic impurities in certain gutter oil were given as follows:42 . 7 mg/kg for acetic acid, 21. 6 mg/kg 3-butenenitrile, 71. 8 mg/kg carbon disulfide and 2. 8 mg/kg allylisothiocyanate.