AssayIndex
Glossary

Terms beginning with T

10 of 238 glossary terms.

Tailing factor (T)
Peak shape measure at 5 % of peak height: (a + b)/2a. USP convention; related to but not identical with the asymmetry factor.
Tangent skim
Integrating a small peak on the trailing edge of a much larger one by drawing a tangential baseline. The convention above a height ratio of about 10:1.
Trifluoroacetic acid (TFA)
Mobile-phase additive at 0.1 %. Gives excellent peptide peak shape and suppresses electrospray ionisation. Also the most common peptide counter-ion.
Time-of-flight (TOF)
A mass analyser measuring the time for ions to traverse a flight tube. High resolving power; calibration is temperature-sensitive.
Target-compound content
Total peptide content multiplied by chromatographic purity. The fraction of the vial that is the named compound. The number that determines recovered mass.
TFA adduct
A trifluoroacetylated peptide, +95.982 Da, formed during cleavage or from prolonged exposure to trifluoroacetic acid.
Truncation
A peptide missing residues from one terminus. Distinguished from an internal deletion by the mass difference matching a contiguous run of residues.
tBu residual
Incompletely removed tert-butyl side-chain protection, +56.063 Da. Indicates a short or weak cleavage step.
see also Fmoc
Threshold pyrogenic dose (K)
5.0 EU per kilogram per hour for parenteral routes, 0.2 EU/kg for intrathecal. Converting it to a per-milligram limit requires the dose.
Tukey fence
Q1 − 1.5 IQR and Q3 + 1.5 IQR. The convention for defining box-plot whiskers and outliers.
see also Outlier