What are the Molar Extinction Coefficient Units in ASTRA?

ENVIRONMENT

Software:

• ASTRA 6
• ASTRA 7
• ASTRA 8
• ASTRA V

ANSWER

In ASTRA, the extinction coefficient for the UV detector must be entered in mass concentration units. ASTRA versions 6, 7, and 8 use units of mL/(mg·cm), while ASTRA V uses mL/(g·cm). To convert from molar extinction coefficients to the required mass-based units in ASTRA 6/7/8, use the formula:
εmass [mL/(mg·cm)] = εmolar [L/(cm·mol)] / Mw [g/mol].
For ASTRA V, the conversion is:
εmass [mL/(g·cm)] = εmolar [L/(cm·mol)] / Mw [g/mol] × 1000 [1].

ADDITIONAL INFORMATION

ASTRA requires that the extinction coefficient for the UV detector (UV extinction coefficient) is entered in mass concentration units.

Note: ASTRA 6/7/8 and ASTRA V use different units. ASTRA 6/7/8 use mL/(mg*cm) and ASTRA V uses mL/(g*cm)