Thursday, 17 May 2012

08:01 – Barbara spent most of yesterday at the hospital. Her mom is doing better. She may be released today or tomorrow. Barbara came home yesterday afternoon for a couple of hours to shower, pick up some clothes, and see Colin and me. She headed back down to the hospital around dinnertime to have dinner with her dad and sister, visit with her mom, and then spend the night with her dad at her parents’ house. She’s going into work today, and may or may not be home this evening.

I got started yesterday on the final lab session for the forensics book. This is the one I skipped back in the first group of lab chapters on soil analysis. I knew I wanted to do a session on chemical analysis of soil, but at that point I wasn’t sure exactly what I wanted to do. I decided to do an assay of soluble inorganic phosphates using molybdate reagent, which is a 1% to 2.5% w/v solution of ammonium molybdate in a 30% to 40% aqueous solution of sulfuric acid. This reagent provides a quantitative color change in the presence of inorganic phosphates, and is sensitive down to the sub-ppm level.