How difficult is it to produce qualified AR-grade potassium hydroxide?
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I often use potassium hydroxide; I buy it from two suppliers in Shenyang. For the first one, I used about 40 bottles; around 30% of them turned pink, while some turned black, and there were also black particles after dissolution. The black particles are visible to the naked eye; some are about 1 mm in size, can float on top of the solution, and can be collected. Some bottles of black particles can yield over 50 pieces. In the second case, about 50% contain black particles, and around 10 such particles can be found in one bottle. I only encountered the pink issue once. I’m not familiar with the production process for potassium hydroxide; I think it’s possible to ensure that there are no visible impurities in it, right? Everyone is welcome to share their thoughts. I ordered this time from Tianjin; I’ll compare it once it arrives. I have used many reagents from Tianjin in the past, and they were all very good. To be honest, I still want to support locally produced products from Shenyang, but it’s a bit frustrating. I’ve been using it for over half a year, in many batches; its performance has been good at times and poor at other times.
This time I bought one made in Tianjin, and it’s actually chocolate-colored. 7 yuan per bottle; I bought a box. The manufacturer’s attitude toward the product – products of this color are placed in AR bottles. . . . . Today I bought another one from a company in Tianjin; the pictures they sent me showed that potassium hydroxide is white in color. Try it after it arrives. This time it’s 6 yuan cheaper per bottle; buying a box… I compared them, and although the color this time is more of a dark purple, it looks a bit chocolatey. It dissolves more easily than the version produced in Shenyang before, releases more heat, and has a higher potassium hydroxide content. After checking the manual, I found that industrial-grade potassium hydroxide comes in purple color; it meets Standard I, with a purity level of up to 90%. The purity of the bottles from Tianjin is 85%, while those from Shenyang have a purity of 82%. But I think these figures are just made up. I would like to ask here: regarding potassium hydroxide of grade AR, what is the relationship between price and quality? Is it true that you get what you pay for, or does it depend entirely on luck? The quality of products priced at 6 yuan may not necessarily be better than that of those priced at 15 or 20 yuan.