colorimetric solution
1.The current test method of heavy metals in edible alcohol is adopted colorimetric method using hydrogen sulphide saturated solution as colorific agent, this method is toxic, disagreeable odour, contaminated, overlaborated and time expended.
2.The solution of the crystal Al_(13) is studied by using Al-Ferron time complex colorimetric method, and find the content of Al_b is up to 71.23%.
3.Based on the principle of determining the residual chlorine by using DPD colorimetric method in ISO 7393/2, the experimental procedure, especially some problems in making calibration curve by using KIO_3-KI standard solution were discussed and an improved procedure was proposed. It is shown from the experimental results that the improved procedure can eliminate the influence of NH_2Cl on the determination of free residual chlorine and the repeatability of experimental results is also satisfactory.
