08:16 – Barbara’s dad’s IV antibiotic course finishes tomorrow. She has to take him to a follow-up visit to his doctor Tuesday, so she’s going to pick him up from the rehab facility and take him back to his apartment after he visits the doctor. She says he’s up and about, which is all that’s necessary to make his own apartment the best place for him. The last thing Barbara and Frances want to do is split up their mom and dad, so they intend to keep him at the Creekside retirement village as long as possible. If/when there’s another crisis, they’ll get him to the hospital and wait until he’s well enough to come straight back home. They don’t want him in a nursing home until/if it’s completely unavoidable.
The heat sealer I ordered from Amazon arrived yesterday, and I immediately put it to the test by sealing a couple of bottles of iodine solution in a quart ziplock bag. The bags are 2-mil (0.05+ mm) polyethylene, and it takes only a couple seconds for the sealer to melt a seal into the bag. I intentionally left plenty of air in the bags so that I could check them for airtightness. They are in fact airtight, but unfortunately that doesn’t stop the iodine vapor from penetrating the bag. There’s a very, very slight iodine odor, but that’s good enough to keep the iodine vapor from staining other parts in the kits. We’re going to start including a separate iodine bottle label that people can affix to the bottle once they open the bag. I’ll probably also use the heat sealer to seal the other chemical bags in the kits.
11:36 – Barbara and I just got back from Lowe’s. We needed some 4-foot fluorescent tubes for the basement fixtures, so we picked up a 10-pack for $22. I think I’ll date the things with a Sharpie before I install them. I think some of the current tubes are original from when we installed the fixtures back in the late 80’s and early 90’s.
While we out there, I decided to pick up some chemicals for the kits. Most of the chemicals we use are reagent-grade, lab-grade, or USP, purchased from lab chemical vendors. But three of them we get from Lowe’s or Home Depot, because we use them in relatively large amounts and they’re much cheaper at a DIY super-center than they are from lab vendors. The purity is adequate for our purposes. Those three are copper(II) sulfate pentahydrate (sold as Root Kill), sodium hydroxide (sold as Crystal Drain Opener), and hydrochloric acid (sold as muriatic acid).
Years ago, before I decided to use them, I did gravimetric analyses on the copper(II) sulfate and sodium hydroxide. The Root Kill ($13 for two pounds/907 grams) is labeled as 99% copper(II) sulfate. When I tested it gravimetrically, it assayed at, IIRC, 99.7±0.1%, which is essentially reagent-grade in terms of purity. The remaining 0.3% give or take is probably almost all insoluble copper(II) oxide, which is easy to filter out. The Crystal Drain Opener is labeled as 100.0% sodium hydroxide. Gravimetrically, I got about 99.5% sodium hydroxide, but I suspect it really is 100.0% in the bottle. The problem with sodium hydroxide is that it literally sucks water vapor out of the air. You can put some dry sodium hydroxide in a weigh boat and watch the weight increase as the dry crystals absorb water. The muriatic acid is probably about lab grade in terms of purity. The stuff is manufactured simply by bubbling hydrogen chloride gas into water, so most of the contaminants in the products were in the source water. Still, it’s more than good enough for our purposes.
I also picked up a gallon (3.8 liters) of acetone in the paint department for something like $4.50 a liter. It’s certainly not spectroscopic-grade nor even reagent-grade acetone, but again it’s more than pure enough for our purposes. Acetone is produced commercially mostly directly from propylene by the cumene process or by oxidizing isopropanol, so the process itself inherently produces pretty pure product. Other than water, the only contaminants are typically low concentrations of VOCs that have no effect on the acetone for solvent purposes. We use it 50/50 with USP-grade 70% IPA for making up Sudan III stain. I’ve tested that stain made up with reagent-grade solvents, and there’s no visible difference in results compared to stain made up with the USP and technical-grade solvents.