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Glossary

Terms beginning with B

11 of 238 glossary terms.

Backpressure: The pressure the pump develops to push mobile phase through the column. Rising backpressure across a sequence indicates a blocking frit or a fouled column inlet.
Baseline: The detector signal in the absence of an eluting analyte. On a gradient it drifts, and where the baseline is drawn determines the integrated area.
Base peak: The most intense peak in a spectrum. For a 4 kDa peptide by electrospray it is usually the 4+ charge state.
Bacterial endotoxin: Lipopolysaccharide from gram-negative bacterial outer membranes. Pyrogenic, filter-passing, autoclave-stable, and invisible to every chromatographic method.
Bioburden: The viable microbial count in a non-sterile article. Distinct from sterility, which is a presence/absence test.
Bland–Altman analysis: Paired comparison of two measurement methods by plotting difference against mean. Yields a bias and limits of agreement. Used for inter-lab agreement here.
Bias: A systematic offset between a measurement and a reference. Distinct from scatter: bias in one direction across many observations is a different finding from random disagreement.
Bootstrap: Estimating a confidence interval by resampling the observed data. Useful where a supplier cell is too small for a parametric interval.
Buyer-sourced: Purchased through the supplier's ordinary retail channel by the submitter, with no supplier involvement. The strongest provenance class here.
Batch rollup: All reports in the index for one physical lot, with a reproducibility assessment across independent tests.
Bacteriostatic water: Water containing 0.9 % benzyl alcohol as a preservative. The benzyl alcohol absorbs strongly in the UV and adds peaks to a chromatogram.