Table I.

Certified absorbance values for the components of SRM 2082 and the reference value decadic attenuance (DA) for RM 8671. SRM 2082 is Standard Reference Material (SRM) 2082.

Test sample	Absorbance 260 nm	Absorbance/DA 280 nm
Tryptophan		8.350 ± 0.003*
Uracil	7.990 ± 0.003*
NISTmAb (DA)		14.204 ± 0.026**
NISTmAb (wavelenth dependent corrected scattering at 320 nm to 340nm)		14.125 (S.D. 0.008)***
NISTmAb (simple correction at 320 nm)		14.145
NISTmAb (simple correction at 340 nm)		14.174

^*The uncertainties were calculated as described in the NIST certificate of analysis for SRM 2082 and

^**decadic attenuance (DA), standard type A uncertainty (9), report of investigation for RM 8671 (see certificates at www.nist.gov/srm).

^***The DA was corrected for protein scattering done using the DA values from 320 nm to 340 nm as described in the text (13).