Multivariate statistical techniques, cluster analysis (CA) and principal component analysis (PCA) were applied to the data on water quality of Manchar Lake (Pakistan), generated during 2005–06, with ...monitoring at five different sites for 36 parameters. This study evaluated and interpreted complex water quality data sets and apportioned of pollution sources to get better information about water quality and to design a monitoring network. The chemical correlations were observed by PCA, which were used to classify the samples by CA, based on the PCA scores. Three significant sampling locations—(sites 1 and 2), (site 4) and (sites 3 and 5)—were detected on the basis of similarity of their water quality. The results revealed that the major causes of water quality deterioration were related to inflow of effluent from industrial, domestic, agricultural and saline seeps into the lake at site 1 and also resulting from people living in boats and fishing at sites 2 and 3.
The simple and rapid pre-concentration techniques viz. cloud point extraction (CPE) and solid phase extraction (SPE) were applied for the determination of As
3+ and total inorganic arsenic (iAs) in ...surface and ground water samples. The As
3+ was formed complex with ammonium pyrrolidinedithiocarbamate (APDC) and extracted by surfactant-rich phases in the non-ionic surfactant Triton X-114, after centrifugation the surfactant-rich phase was diluted with 0.1
mol
L
−1 HNO
3 in methanol. While total iAs in water samples was adsorbed on titanium dioxide (TiO
2); after centrifugation, the solid phase was prepared to be slurry for determination. The extracted As species were determined by electrothermal atomic absorption spectrometry. The multivariate strategy was applied to estimate the optimum values of experimental factors for the recovery of As
3+ and total iAs by CPE and SPE. The standard addition method was used to validate the optimized methods. The obtained result showed sufficient recoveries for As
3+ and iAs (>98.0%). The concentration factor in both cases was found to be 40.
The concentrations of heavy metals (HMs) in plants served to indicate the metal contamination status of the site, and also revealed the abilities of various plant species to take up and accumulate ...them from the soil dressed with sewage sludge. A study to comprehend the mobility and transport of HMs from soil and soil amended with untreated sewage sludge to different newly breaded varieties of wheat (Anmol, TJ-83, Abadgar and Mehran-89) in Pakistan. A pot-culture experiment was conducted to study the transfer of HMs to wheat grains, grown in soil (control) and soil amended with sewage sludge (test samples). The total and ethylenediaminetetraaceticacid (EDTA)-extractable HMs in agricultural soil and soil amended with domestic sewage sludge (SDWS) and wheat grains were analysed by flame atomic absorption spectrometer/electrothermal atomic absorption spectrometer, prior to microwave-assisted wet acid digestion method. The edible part of wheat plants (grains) from test samples presented high concentration of all HMs understudy (mg
kg
−1). Significant correlations were found between metals in exchangeable fractions of soil and SDWS, with total metals in control and test samples of wheat grains.
The bio-concentration factors of all HMs were high in grains of two wheat varieties, TJ-83 and Mehran-89, as compared to other varieties, Anmol and Abadgar grown in the same agricultural plots.
A fast microwave assisted extraction procedure was developed and optimized for their eventual exploitation in the three-stage sequential extraction procedure proposed by modified BCR protocol (the ...community Bureau of Reference now the European Union “Measurement and Testing Programme”). The effects of the microwave treatment on the extraction of Cd, Cr, Cu, Ni, Pb and Zn from untreated sewage sludge collected from Hyderabad city (Pakistan) were compared with those obtained from sequential BCR extraction procedure. In sequential BCR method, each extraction step takes 16
h, where as with the use of compromised microwave conditions, extraction steps could be completed in about 120
s, for each step, respectively. Extractable Cd, Cr, Pb and Ni obtained by both comparable methodologies were measured by electrothermal atomic absorption spectrometry (ETAAS), while for Cu and Zn flame atomic absorption spectrometry (FAAS) was used. The validations of both extraction techniques were compared by the analysis of certified reference material of soil amended with sewage sludge (BCR 483). The results of the partitioning study of untreated waste water sewage sludge, indicate that more easily mobilized forms (step 1) were predominant for Cd, Ni and Zn (28.3, 28.4 and 43.7%), in contrast, the largest amount of Cd and Pb (66.4 and 72.8%) was associated with the iron/manganese oxide while Cr and Ni (71.2 and 38.7%) in organic matter/sulphide fractions. The overall metal recoveries in steps 1–3 (excluding residual step) were 95.3–104% of those obtained with the sequential BCR protocol. The accuracy of the proposed microwave extraction method (expressed as %R.S.D.) was lower than 10% for all metals.
In present study a biomass derived from the stem of
Acacia nilotica has been investigated to remove As ions from surface water samples of different origins (lake, canal and river). The effects of ...various parameters viz. pH, biosorbent dosage, contact time and temperature on the biosorption processes were systematically studied. Experimental data were modeled by Langmuir, Freundlich and Dubinin–Radushkevich (D–R) isotherms. It was observed that As biosorption best fitted to the Langmuir and Freundlich isotherms. The mean sorption energy (
E) calculated from D–R model, indicated physico-chemical biosorption. Study of thermodynamic parameters revealed the endothermic, spontaneous and feasible nature of biosorption process. The pseudo-second-order rate equation described better the kinetics of As biosorption with good correlation coefficients than pseudo-first-order equation. The biomass of
A. nilotica was found to be effective for the removal of As with 95% sorption efficiency at a concentration of <200
μg/L of As solution, and thus uptake capacity is 50.8
mg As/g of biomass. The
A. nilotica biomass could be used as a low-cost biosorbent for As ion removal.
A new method is reported for the separation of aluminum ions Al(III) from interfering elements in parenteral and pharmaceutical solutions (PS) and bottled mineral water (BMW) samples, through ...solid-phase extraction with 2-methyl-8-hydroxyquinoline (quinaldine) adsorbed onto activated silica gel. While the enrichment step of separated Al(III) was carried out by cloud point extraction (CPE) using 8-hydroxyquinoline as complexing reagent, the resulted complex was entrapped in a non-ionic surfactant octylphenoxypolyethoxyethanol (Triton X-114). The enriched Al(III) in sample solutions were determined by spectrofluorometry (SPF) at
λ
excitation 370
nm and
λ
emission 510
nm, and flame atomic absorption spectrometry (FAAS) for comparative purpose. The variables affecting the complexation and extraction steps were studied and optimized. The validity of methodology was checked with certified reference material of water and standard addition method. The enrichment factor and detection limit of Al(III) for the preconcentration of 50
ml of PS and BMW were found to be 100 and 0.25
μg/L, respectively. The proposed method has been applied for the determination of trace amount of Al(III) in PS and BMW samples with satisfactory results. In PS the levels of Al(III) are above than permissible limit (25
μg/L).
A cloud point extraction (CPE) method has been developed for the determination of trace quantity of vanadium ions in pharmaceutical formulations (PF), dialysate (DS) and parenteral solutions (PS). ...The CPE of vanadium (V) using 8-hydroxyquinoline (oxine) as complexing reagent and mediated by nonionic surfactant (Triton X-114) was investigated. The parameters that affect the extraction efficiency of CPE, such as pH of sample solution, concentration of oxine and Triton X-114, equilibration temperature and time period for shaking were investigated in detail. The validity of CPE of V was checked by standard addition method in real samples. The extracted surfactant-rich phase was diluted with nitric acid in ethanol, prior to subjecting electrothermal atomic absorption spectrometry. Under these conditions, the preconcentration of 50
mL sample solutions, allowed raising an enrichment factor of 125-fold. The lower limit of detection obtained under the optimal conditions was 42
ng/L. The proposed method has been successfully applied to the determination of trace quantity of V in various pharmaceutical preparations with satisfactory results. The concentration ranges of V in PF, DS and PS samples were found in the range of 10.5–15.2, 0.65–1.32 and 1.76–6.93
μg/L, respectively.
The aim of this study was to evaluate the uptake of arsenic (As) by grain crops (wheat, maize and sorghum) grown on agricultural soil irrigated with tube well water (SIT) as test samples and for ...comparative purposes, same grain crop samples grown on agricultural soil irrigated with fresh canal water (SIC) were marked as control samples, collected simultaneously from three sub-districts of Khairpur, Pakistan. Moreover, this paper demonstrated the total and EDTA (0.05M) extractable As in both understudied soils that correlate with the respective total As in the edible parts of the studied grain crops. A significantly high accumulation of As was found in grains grown on SIT as compared to those grown on SIC. This study highlights the increased danger of growing food crops in the agricultural land continuously irrigated by As contaminated ground water.
In present work concentrations of toxic elements (TEs), aluminum (Al), cadmium (Cd), and lead (Pb) in seventeen imported samples of infant milk-based (IMF) and infant soy-based formulae (ISF), were ...measured, to evaluate whether the intakes of understudy TEs accomplished within recommended permissible levels. The TEs were analyzed by electrothermal atomic absorption spectrometer, prior to microwave induced acid digestion. The validity of methodology was tested by simultaneously analyzing certified reference material and standard addition method. It was observed that ISF contains higher concentration of understudy toxic analytes as compared to IMF. The all three TEs, Al, Cd and Pb were detected in different branded infant formulae, in the range of (1070–2170), (10.5–34.4), and (28.7–119) μg/kg, respectively. The estimated intakes of TEs as μg/kg/week for infants (>1
year) through milk formulae are well below the recommended tolerable levels of these elements.
A separation/preconcentration of aluminum (III) (Al
3+) has been developed to overcome the problem of high matrix species, which may interfere with the determination of trace quantity of Al
3+ in ...natural water samples. The separation of Al
3+ in water samples was carried out from interfering cations by complexing them with 2-methyle 8-hyroxyquinoline (quinaldine) on activated silica. Whereas the separated trace amounts of Al
3+ was preconcentrated by cloud point extraction (CPE), as prior step to its determination by spectrofluorimetry (SPF) and flame atomic absorption spectrometry (FAAS). The Al
3+ react with 8-hydroxyquinoline (oxine) and then entrapped in non-ionic surfactant Triton X-114. The main factors affecting CPE efficiency, such as pH of sample solution, concentration of oxine and Triton X-114, equilibration temperature and time period for shaking were investigated in detail. The validity of separation/preconcentration of Al
3+ was checked by certified reference material of water (SRM-1643e). After optimization of the complexation and extraction conditions, a preconcentration factor of 20 was obtained for Al
3+ in 10
mL of natural water samples. The relative standard deviation for 6 replicates containing 100
μg
L
−1 of Al
3+ was 5.41 and 4.53% for SPF and FAAS, respectively. The proposed method has been applied for determination of trace amount of Al
3+ in natural water samples with satisfactory results.
