First, in order for you all to understand what a month September has been for me, I’ll outline how my job usually works. I’m sorry if this is all too technical, but in order to understand why September was so sucky, you’re going to have to bear with me. I'm color-coding a few things to help you keep it all straight.
Usually I come in in the morning and start weighing out samples for testing. From Our Production Plant (O.P.P.) we usually get somewhere between 15 and 35 samples (sometimes more or less) for heavy metals testing. From Company I Do Hg For (C.I.D.H.F.) (Hg=Mercury), I usually get between 10 and 25 samples for Hg testing only (again, sometimes more or less) (and during this whole series of posts, I won't be talking much about the Hg samples). From other outside clients, I usually get 10 samples or so (but there’s the occasional client who will send me 20+ all at once, bless their hearts…). So, on a usual day, we’re talking between 25 and 60 samples for heavy metals testing and 10 to 25 samples for Hg testing (but these aren't very important in the story to come). Remember these numbers.
Normally, I run Hg on my DMA (Direct Mercury Analyzer). If this instrument is down due to either malfunction or regular maintenance, I can use my ICP-MS (Inductively Coupled Plasma-Mass Spectrometer). If I’m not there, then for simplicity’s sake my boss just runs Hg on the ICP-MS (and doesn’t do any testing for our outside clients unless it’s a rush). If the ICP-MS is down, then we just can’t do Hg testing (well, technically we could do it on the ICP-OES (Inductively Coupled Plasma-Optical Emission Spectrometer) but it takes two days to prep the samples for that method, and then there’s a special equipment setup…basically, it’s a pain in the ass). For other heavy metals testing, I usually use my ICP-MS. If this instrument is down, we have a backup method on our ICP-OES that works for most of our own products. There are a few interferences, so for the samples that don’t work on the ICP-OES that we really need results on ASAP, we usually send these samples over to C.I.D.H.F. and since our companies are friends, they will run those few samples for us on their own ICP-MS, and when their instrument is down, they send us their samples, so it’s a you-scratch-my-back-I’ll-scratch-yours sort of thing. Also important: Coworker runs mineral assays on the ICP-OES. When it’s down, the ICP-MS is the backup for his testing.
Calibration on my normal ICP-MS run usually takes about 50 minutes (sometimes more or less, depending on the method I need to run for the day), and after that each sample takes about 3.75 minutes to run. Every ten samples, I need to run a QC (quality control) sample (or two, or three, depending on the method) and a blank.
So let’s say I’m having a totally average day and I have 40 samples for heavy metals testing. That’s 50 minutes for calibrating, 150 minutes for samples, and 45 minutes for QCs and blanks. 245 minutes = roughly 4 hours. If I start my run around 10:30 a.m., I can get off of work at a normal time. I usually work 7 hours a day. Most days, I don't have to share the ICP-MS with anyone, or I can at least finish all of my work before anyone else needs it. If I absolutely need to, I can let it run many, many more samples overnight.
And that’s how life normally is in my lab.
To be continued…