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|Title: ||Speciation of arsenic in some biological samples from Obuasi and its surrounding villages|
|Authors: ||Sarkodie, Peter Abum|
|Issue Date: ||16-Jul-1996|
|Series/Report no.: ||2239;|
|Abstract: ||Arsenic speciation was done in Pteris vitstae (ferm), Musa sapientum ( plantain), colocasia esculenta (cocoyam), leaves of colocasia esculenta, Manihot ecsulentum (cassava) ,leaves of Manihot esculentum, Capsicum frutescens (pepper) and Elaeis guinensis (palm fruits). The methods used in the speciation were the colorimetric molybdenum blue and ion-exchange. AAS was used to determine total arsenic in the samples and total arsenic determined by the molybdenum blue method were found to correlate with those obtained by AAS. Also, arsenic (V) and arsenic (III) values obtained by ton exchange were found to correlate with those obtained by the molybdenum blue method.
All the plant contained higher concentrations of arsenic (V) than arsenic (III). The molybdenum blue and ion-exchange methods, gave maximum mean arsenic (V) concentrations as 32.28 Std.± 5.44mg/kg and 31.29 Std.± 5.44mg/kg dry weight respectively. These values of arsenic (V) were recorded in fern at Kwabrafoso. The minimum mean arsenic (V) concentrations, however, was 0.07 Std.±0 06mg/kg dry weight in each of the two methods. This value of arsenic (V) concentration was recorded in palm fruits at Ampunyase.
The maximum mean arsenic (III) values by both molybdenum and ion- exchange methods were 7.26 Std. ± 1.68mg/kg and 8.24 Std ±1.74mg/kg dry weight respective]y. These values were recorded in fern at Kwabrafoso. The minimum arsenic (III) concentration by both methods however, was 0.00mg/kg dry weight and was recorded in palm fruits at Ampunyase.
Arsenic (V) and arsenic (III) levels in the samples increased during the rainy season.
Mean arsenic (V) concentrations determined by both methods wan higher than the W.H.O. recommended value of 1.0mg/kg dry weight n fern for all the fourteen sampling sites. For those sates which were within 3.75km from the treatment plant, mean arsenic (V) concentrations determined by both the molybdenum blue and ion- exchange methods were higher than the W.H.O recommended value in all the samples except palm fruits. From 5.0km and beyond, mean arsenic (V) concentrations by both methods were below the W.H.O.recommended value in plantain, cocoyam, cocoyam leaves, cassava, cassava leaves, pepper and palm fruits.
Apart from fern, mean arsenic (III) concentrations in the samples at alt the sites were below 1.0mg/kg dry weight by both methods. From 8.50km and beyond, mean arsenic (III) concentrations in palm fruits were drastically low.
Mean arsenic (III) concentrations determined by ion-exchange were quite higher than those obtained by the molybdenum blue method|
|Description: ||A thesis submitted to the Board of Postgraduate Studies, Kwame Nkrumah University of Science and Technology, Kumasi, in partial fulfilment of the requirement for the award of the Degree of Master of Philosophy in Environmental Chemistry, 1996|
|Appears in Collections:||College of Science|
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