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Parts-per-billion levels of cadmium and lead were detected using square-wave anodic stripping voltammetry with a boron-doped diamond electrode. Calibration plots (10-minute deposition time) in KCl and KNO 3 were non-linear at low concentrations (1 ± 5 ppb) due to the deposition mechanism of these metals. The preferred electrolyte for cadmium was KCl, while lead could be measured in either electrolyte. The lowest concentrations included in the linear portion of the calibration plot (5 minute deposition time) for cadmium were 10 ppb and 50 ppb in KCl and KNO 3 , respectively, and 10 ppb for lead in KNO 3 . The presence of either lead or copper suppressed the cadmium stripping peak, but the lead stripping peak was unaffected by cadmium, and enhanced by the addition of copper. A river water sample was analyzed for cadmium and lead, and the cadmium results were confirmed using ICP-AES spectrometry. It was determined electrochemically that a fraction of lead in the river sample was bound by complexing material in the sample.

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JV-Methyl-2-pyrrolidinone (NMP) is widely used in coal extraction. It has been shown that NMP is strongly retained in coal extracts and the retained NMP affects the character of the extracts. In order to calculate the actual extraction yield and understand the interaction between NMP and coal, the amount of NMP retained by its coal extracts must be quantified. TGA-FTIR has been applied to the quantitative analysis of NMP. Neutral aluminum oxide with 4.74% NMP added was used as a standard, and a linear calibration curve for the area of the NMP profile and the retained NMP weight was obtained. Several NMP-soluble coal extracts were tested by this method. The percentage of the NMP retained by these extracts varied from 1.08 to 3.40% with deviations ( = 2) within 0.25%. The detection limit can be as low as 5 µg with a S/N of 5 when the C=0 stretching band of NMP is used.