Voltage Scanning Coulometry for the Determination of Traces of Iron
Blanks equivalent to 0.2 mu eq. establish the detection limit of many controlled potential coulometric procedures. To permit lower detection limits, in the region of 10-3 μeq., a new electroanalytical technique called voltage scanning coulometry has been developed and its parameters investigated. The procedure is based upon the measurement of the electrolysis current passed while the potential between the sample solution and a working or titrating electrode is scanned at a uniform rate. During the scan, every effort is made to eliminate concentration polarization of the working electrode, and a complete titration is, therefore, effected. The major portion of the current due to the blank is distributed uniformly along the curve and can be distinguished readily from the current due to the titration which appears as a peak. The procedure and apparatus are simple and the determination is rapid. The method has a specificity similar to that of derivative polarography. Several possible applications of the technique are suggested, and its use in the determination of trace quantities of iron is discussed in detail. A detection limit for iron of 5 x 10-4 mu eq. (0.025 μg.) per sample or, assuming a 5-ml sample, of 10-7M and a standard deviation of plus or minus 0.02 μg. have been obtained. Possible refinements to improve further the sensitivity are indicated.
- Research Organization:
- General Electric Co., Richland, Wash.
- Sponsoring Organization:
- USDOE
- NSA Number:
- NSA-15-022262
- OSTI ID:
- 4044201
- Report Number(s):
- HW-SA-1848; 0003-2700
- Journal Information:
- Analytical Chemistry, Journal Name: Analytical Chemistry Journal Issue: 8 Vol. 33; ISSN 0003-2700
- Publisher:
- American Chemical Society (ACS)
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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