ISSN:
1573-2932
Keywords:
selective leach
;
organic
;
humic
;
fulvic
;
analysis
;
mercury
;
zinc
Source:
Springer Online Journal Archives 1860-2000
Topics:
Energy, Environment Protection, Nuclear Power Engineering
Notes:
Abstract The international reference lake sediment, LKSD-4, was used to compare Hg, organic C and Zn extracted from its 'soluble organic' phase by two commonly used reagents: 0.1 M Na4P2O7 solution at pH 10 and 0.5 M NaOH solution at pH 12. While recoveries of Hg and Zn by 0.1 M Na4P2O7 are not affected by changes in sample weight to reagent volume ratio (W/V) or contact time, those by NaOH show a marked dependency. In general, the NaOH leach extracts more organic C and Hg from LKSD-4 but less Zn. Over the range of conditions studied, the NaOH-based method extracted 4.7-9.8% C, 27-103 ng g-1 Hg and 19-69 µg g-1 Zn from LKSD-4, compared to 2.3-2.8% C, 17-24 ng g-1 Hg and 64-72 µg g-1 Zn by the Na4P2O7 leach. Clearly, different groups of organic substances are being dissolved by these two reagents and therefore a comparison of data from different laboratories becomes meaningless. This paper suggests that more research is needed into the exact nature of metal-organic associations extracted by selective leaches and into associated artifacts of extraction such as readsorption phenomena.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1018317407840
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