2. The standard solution should be prepared and determined (at the same time as the sample), and the result of preparation one day in advance cannot be guaranteed;
3. Thiourea and ascorbic acid need to be added in the determination of arsenic;
4, reagent meets the requirements, instruments to soak in acid overnight, clean.
Arsenic, commonly known As arsenic, with element symbol as, is a nonmetallic element, which is located in the 4th period of the periodic table of chemical elements, and belongs to VA family with atomic number 33. Simple substance exists in the form of three allotropes: gray arsenic, black arsenic and yellow arsenic.