[Lab] 18th independent test on SWB — 99.4% on a claimed 99.0%, and the trend is the interesting part
Numbers in the title, numbers in the post. 18th independent test on SWB — 99.4% on a claimed 99.0%, and the trend is the interesting part. Numbers, in the order they matter: 99.4% and 99.0%. Gave the same trace to two people I trust and got two integrations about a point apart. That was the most educational afternoon…
Resolution between two peaks depends on retention, selectivity and efficiency. A shallower gradient buys retention and usually resolution, at the cost of peak width and run time.
UV response is not uniform across species. At 214nm you are looking at the peptide bond, which is why it is the working wavelength for this class; at 280nm you only see tryptophan, tyrosine and phenylalanine.
Ran a blank after a high-concentration injection and found the carryover I had been calling an impurity.
Carryover from a previous high-concentration injection looks exactly like a small impurity. The blank injection is four minutes and it removes the ambiguity entirely.
Not convinced by that integration. Dropping the baseline there absorbs part of the shoulder into the main peak.
Chased a ghost peak for three weeks. It was the plumbing. It is always the plumbing.
report the method or do not report the number