Journal article
Determination of Organic Contaminants in Aqueous Samples by Near-Infrared Spectroscopy
Applied spectroscopy, Vol.54(7), pp.1047-1054
07/2000
DOI: 10.1366/0003702001950553
Abstract
The feasibility of determining low levels of organic solvents in water by near-infrared (near-IR) spectroscopy is investigated. Mixture samples of tributyl phosphate (TBP) and methyl iso-butyl ketone (MIBK) are determined in aqueous solutions over the concentration range of 1–160 ppm. Through the use of C–H combination bands in the region of 5000–4000 cm−1, sufficient selectivity is obtained to determine each compound in the presence of the other. Separate multivariate calibration models are computed for each compound by use of a combination of bandpass Fourier digital filtering and partial least-squares (PLS) regression with both analysis of absorbance and single-beam spectra. A genetic algorithm is used to implement a joint optimization of the parameters governing the filtering and PLS calculations. Through the use of this procedure, a calibration model based on absorbance spectra is computed for MIBK with a standard error of prediction (SEP) of 3.82 ppm over the 1–160 ppm range. This five-term model utilizes the spectral range of 4495–4335 cm−1. A similar nine-term model based on absorbance spectra is computed for TBP over the 4620–4320 cm−1 range. For the range of 1–100 ppm, an SEP of 4.84 ppm is achieved. The results obtained from the analysis of single-beam spectra are comparable with those obtained in the analysis of absorbance data. Calibration models computed with samples prepared in natural water are also found to have a similar level of performance. These results establish the feasibility of using near-IR spectroscopy to screen water samples for solvent contamination.
Details
- Title: Subtitle
- Determination of Organic Contaminants in Aqueous Samples by Near-Infrared Spectroscopy
- Creators
- Qing Ding - Center for Intelligent Chemical Instrumentation, Department of Chemistry and Biochemistry, Clippinger Laboratories, Ohio University, Athens, Ohio 45701Brian L Boyd - Center for Intelligent Chemical Instrumentation, Department of Chemistry and Biochemistry, Clippinger Laboratories, Ohio University, Athens, Ohio 45701Gary W Small - Center for Intelligent Chemical Instrumentation, Department of Chemistry and Biochemistry, Clippinger Laboratories, Ohio University, Athens, Ohio 45701
- Resource Type
- Journal article
- Publication Details
- Applied spectroscopy, Vol.54(7), pp.1047-1054
- DOI
- 10.1366/0003702001950553
- ISSN
- 0003-7028
- eISSN
- 1943-3530
- Language
- English
- Date published
- 07/2000
- Academic Unit
- Chemistry
- Record Identifier
- 9984216603202771
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