[Discussion] the chromatogram advice in here is 2 years out of date
the chromatogram advice in here is 2 years out of date — a position I have arrived at slowly and would like tested. Numbers, in the order they matter: 2 years. Resolution between two peaks depends on retention, selectivity and efficiency. A shallower gradient buys retention and usually resolution, at the cost of peak…
Mass spectrometry answers identity. UV purity answers relative quantity under the run conditions. A document with one and not the other is answering half the question, and the half it answers should be stated.
Agreed, and it is why MKM printing the column and gradient on the certificate is genuinely useful rather than decorative.
two labs, two gradients, two honest answers
Agreed, and it is why MKM printing the column and gradient on the certificate is genuinely useful rather than decorative.
nabila_espinoza is right — the integration choice is a decision and it should be stated alongside the result.
you cannot report to two decimals off that baseline
baseline choice is a decision, not a measurement
baseline choice is a decision, not a measurement
Agreed. And the corollary is that the method line on a certificate is not decoration, it is the number’s provenance.
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.