Method for the Detection of Phosphine in Cereals

摘要

A method is described for the total phosphine detection in cereal caryopses, comprising the steps of inserting a sample of cereal caryopses inside a container (1) equipped with hermetic closure (2); adding to the sample an aqueous solution of H₂SO₄ with a v/v concentration in the range of 5-20%, with obtainment of an aqueous dispersion, and hermetically closing the first container (1); subjecting the aqueous dispersion contained in the first container (1) to the action of microwaves for a time not greater than 3 minutes; drawing a predetermined volume of gas overlying the aqueous dispersion and detecting the phosphine possibly present by means of colorimetric and/or spectrophotometric methods, preferably by bringing it into contact with a predetermined volume of an aqueous solution of AgNO₃ of known molarity, inside a second container (3) with hermetic closure and visually analysing the obtained colour and/or spectrophotometrically measuring the absorbance at 400 nm of the aqueous solution. Equipment for the execution of the aforesaid method is described.