Thursday, 19 December 2013

07:54 – We’re in good shape again on biology and chemistry kits, so today I’ll focus on forensic kits. We have everything we need to put together another 30 forensic kits, except half a dozen or so chemicals that we need to make up and bottle before we can assemble the chemical bags.


11:48 – I just finished making up the last two solutions I need to make up more forensic science kits: one liter each of phosphate extraction reagent and molybdate reagent. The first is ammonium sulfate in a solution that’s about 33% sulfuric acid, about the same concentration as battery acid. The second is ammonium molybdate, also in 33% sulfuric acid.

The phosphate extraction reagent made up with no problems, yielding a nice clear pinkish-tan solution. The molybdate reagent was obnoxious, as always. Even with reagent grade chemicals, a scum forms on the top of the solution. Oh, well. At least it’s reagent-grade scum.

I was about to filter the solution when I came to my senses. Pouring 6 molar sulfuric acid into a filter paper cone would char the paper very quickly, so filter paper is a no-go. The first time I made this stuff up, several years ago, I ended up building a sand filter. That worked, at the expense of considerable time and effort, not to mention losing a fair amount of the solution to the filter itself. Subsequently, I’ve always done what I eventually did today; carefully decanted off the clear solution, trying to keep as much of the scum as possible in the beaker. Good enough.