面粉中滑石粉的现场快速检测方法及其装置研究

为建立面粉中滑石粉的现场快速检测方法,并研制出便携式检测装置,实现现场快速检测,通过实验摸索出适合的消化剂配方,即V(H_2SO_4):V(HClO_4):V(HNO_3)=1:1:4;将样品经1 mol/L HCl清洗、加热消化后,取反应液,通过镁试剂的显色反应,定性地判断样品中是否加入滑石粉。结果表明:用样量为1g时,此方法的检出下限为1%,检测时间在40 min左右,重复性较好,假阳性率2.5%,假阴性率2.5%,反应可在密闭的便携武装置内进行,实现现场、快速、无污染检测。

Rapid Detection Method of Talc Powder in Flour

A method and a set of portable equipment for rapid detection of talc powder in flour on the spot was developed.Appropriate digestant(vitrol:perchloric acid:nitric acid=1:1:4)was selected to digest talc powder.After the sample was washed by lmol/L HC1 and digested during heating,p-nitroben- zene azoresorcinol was added into and the change of colour showed whether there was talc powder in the sam- pies.With good repeatability,when the sample was lg,detection limit of this method was 1% and detection time was about 40 min,false positive rate 9.5%,false negative rate 2.5%.Airtight equipment was designed according to this method.Conclusion:The method and the equipment could be practically applied for its accu- racy,rapidity and briefness.