Colorimetric determination of low pH with malachite green. Revision 1 [electronic resource].
- Washington, D.C. : United States. Dept. of Energy, 1994.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy.
- Physical Description:
- 17 pages : digital, PDF file
- Additional Creators:
- Westinghouse Savannah River Company, United States. Department of Energy, and United States. Department of Energy. Office of Scientific and Technical Information
- Restrictions on Access:
- Free-to-read Unrestricted online access
- A spectrophotometric method was developed for determination of concentration-based pH values from 0 to 2 with malachite green indicator. A quadratic model equation was based on the ratio of the absorbances of the peak at 618 nm and the isosbestic point at 518 nm. Normalization to the isosbestic point was used to stabilize the response because the color faded; the useful time interval was within 5 minutes after indicator addition. Model and verification sets agreed within ±0.02 pH units between pH 0.3 and 1.8. This excellent precision makes the colorimetric method useful for acid determinations with a relative precision of >±5%. The presence of salts at a salt/acid equivalent ratio >0.l caused a low pH bias.
- Report Numbers:
- E 1.99:wsrc-ms--93-400-rev.1
- Other Subject(s):
- Published through SciTech Connect.
Baumann, E.W.; Cloessner, P.F.
- Type of Report and Period Covered Note:
- Topical; 04/01/1994 - 04/01/1994
- Funding Information:
View MARC record | catkey: 14394393