The Research For The Determination Of AFB1 In Peanut Using Biosensor

Aflatoxin is one of the strongest known in carcinogenic chemicals,intake of it will cause serious harm in body.Therefore,it is necessary to determine AFB₁ by the methods of qualitative and quantitative.In this paper,we mainly studied the extraction methods of aflatoxin B₁ and enzyme electrode method of aflatoxin B₁.In this study,vortex and ultrasonic agitation technologies were exploited for the AFB₁ extractions.Two methods were determined via response surface analysis:?1?In the vortex method – solid-liquid ratio was 1:5,methanol was 81 %,with the extraction time 12 min and under 1892 rpm of stirring.Production of this method was 2.95 ?g/Kg.?2?In the ultrasonic agitation method – solid-liquid ratio was 1:5,methanol was 65 %,under 63.22 W of ultrasonic power and the extraction time was 8.5 min.In comparison,the ultrasonic agitation method was determined as the optimized extracting conditions.The concrete parameters are as follows: extraction time was 8.5 min,solid-liquid ratio was 1:5,methanol was 65 % and the ultrasonic power was 63 W.After this process,AFB₁ was harvested by carrying out immonoaffinity column.The production of AFB₁ was 5.2 ?g/Kg.An enzyme electrode method for AFB₁ detection was established.In the study,glutaraldehyde concentration and cross-linking time were discussed for optimizing the enzyme membrane preparation conditions.The enzyme electrode is the core component of the biosensing system for AFB₁ detection,therefore,optimal working conditions of the enzyme electrode are required to be determined.The optimal conditions were pinned down by selecting pH,temperature and stirring condition.Feasibility of the method was checked by studying its linear range,limit of detection?LOD?,repeatability,stability and selectivity.The result shown that the optimized conditions were: glutaraldehyde concentration for enzyme immobilization was 2.5 %,cross-linking 3h.The responsing intensity of the electrode reaches the highest level under 40 ?,pH was 7,stirring time was 20 s.The linear range of the electrode was 0-100 ?g/mL with the regressive curve was,?R2 = 0.9984?,RSD is less than 8%,and,the result has relatively ideal fitness towards the HPLC method?R2 = 0.9916?,which was indicative of this method is capable of fast detection of AFB₁ toxin.