Background and Objectives: Although recognized and written about centuries, lead toxicity remains an occupational and public health problem of global dimensions. Several studies have demonstrated that clinical and sub clinical effects of lead toxicity at the blood lead levels considered as safe, i.e., below 30 µg/dl in adults and 10 µg/dl in children. Such studies have received scant attention in the case of lead occupational workers due to the presumption of high blood lead levels in accordance with occupation. In the present study, therefore an attempt was made to investigate the effect of low blood lead levels on indicators of anaemia and renal impairment. Methods: A cohort of 690 subjects who had been occupationally exposed to lead was studied using stratified random sampling design. The markers of anaemia included changes in Haematocrit value, Haemoglobin and Erythrocyte count where as renal health was judged from changes in creatinine clearance rate. The controls were derived from similar socioeconomic background and matched in age and sex with subjects. Blood lead levels were determined by graphite furnace atomic absorption and biochemical determinations carried out using standard procedures. Results: Blood lead levels in the range 10–40 µg/dl had significant effect on anaemia indicators and resulted in inverse co relationship. (Pearson’s correlation coefficient r= -0.65, -0.71 and -0.58 respectively for haematocrit, erythrocyte count and haemoglobin). The creatinine clearance rate estimated after adjustment for body mass index and age factors was found to depend on blood lead level and duration of exposure of subjects. These effects were statistically significant in the subjects having age in the range 15–30 years. Conclusion: Low lead levels in blood have high potential of inducing lead related anaemia by disturbing the pathway of heme synthesis at either ferrochelatase stage or inhibiting the aminolevulinate dehydratase activity. Though creatinine clearance rate did not prove as reliable marker of renal health at low PbB levels but it was successfully used in the case of high PbB levels whereby it could be used to predict the PbB values and vice versa.

Beach sand is used to remove traces of Pb(II) ions from aqueous solutions. Effect of shaking speed, amount of sorbent, shaking time, nature and concentration of different electrolytes and deionized water along with buffer of pH 2345678910 have been studied. Maximum sorption of Pb(II) ions (> 94%) is achieved from 10(-4) M HNO 3 . Sorption data have been tested using Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) sorption isotherms. Thermodynamic parameters such as Delta H, Delta S, and Delta G have been evaluated. Kinetics of sorption is followed by Morris- Weber, Reichenberg and Lagergren equations. Influence of diverse ions on the sorption of Pb(II) ions is also investigated.

ABSTRACT Fatty acid (FA) composition and isomeric trans unsaturated contents in selected brands of margarines and butter, which are more popular among general consumers of Pakistan, has been reported in this study. A sum of 10 butter and 10 margarine samples, collected from different bakers, confectioners and retail outlets, was analyzed. FA methyl esters were prepared, and quantitative measurements were made using a methyl lignoserate‐coated stationary phase, capillary column (SP‐2340, 60 m × 0.25 mm, 0.20 μm), with flame ionization detection. The contents of saturated FA, cis monounsaturated FA and cis polyunsaturated FA were in the following ranges: margarines 38.9–53.1, 21.9–35.8, 7.45–21.5% and butter 63.7–68.5, 23.0–27.0 and 1.20–2.94%, respectively. Results showed significantly higher amounts of trans FA (TFA) in margarines ranged from 2.45 to 21.1%, whereas butter samples contained less than 5.00% of TFA.

The present method utilizes styrene-divinylbenzene-based polymeric material containing phthalic acid as chelating agent to concentrate ultra trace amounts of indium ions in aqueous solutions. Sorption behaviour of In(III) ions under static and dynamic conditions onto the new synthetic resin is reported here. Maximum sorption has been achieved from solution with 8 min of agitation time in the pH range 5-8. The lowest concentration for quantitative recovery is 5 ppb with the preconcentration factor 666. The kinetics and thermodynamics of sorption have been studied in detail. The kinetics follows the first order rate equation with the rate constant k, equal to 0.645 +/- 0.05 min. The variation of equilibrium constant k(c) with temperature between 10 degrees C to 50 degrees C yields values of Delta H 33.7 +/- 1.96 kJmol(-1), Delta S 136.9 +/- 6.4 Jmol(-1)K(-1) and Delta G(303K) -7690 +/- 200 Jmol(-1)K(-1). The sorption data in the concentration range 5.26 x 10(-6) to 2.19 x 10(-4) M L-1 In(III) ions follow Langmuir, Freundlich, and Dubinin-Radushkevich isotherms at all the temperatures investigated. The sorption of In(III) ions onto the synthesized resin in the presence of common anions and cations has also been measured.

An analytical procedure has been developed for the analysis of benzoic acid, p-hydroxybenzoic acid, methyl-, ethyl-, propyl-, isopropyl-, and butyl esters of p-hydroxybenzoic acid by micellar liquid chromatography. After dilution in n-propanol the sample was directly injected onto a Lichrosorb ODS, 5 microm (250 x 4.6 mm ID) column and eluted with aqueous 2% Brij-35 adjusted to pH 3.0 with phosphoric acid:propanol (80:20 v/v) at a flow rate of 1 mL min(-1) and UV detection at 254 nm. A linear calibration curve was obtained simultaneously for each component in the range of 50-500 microg mL(-1) for benzoic acid and 5-150 microg mL(-1) for the other components; detection limits were within 25-250 ng mL(-1) corresponding to 125-1250 pg per injection (5 microL). The reproducibility in terms of average peak area and average retention time was obtained with coefficients of variation (CV) of 1.2% and 0.5%. The method was applied to analysis of these compounds in cosmetics (shampoos, hand lotions, creams, and bath foam) and food samples.

Sensitive cathodic stripping voltammetric methods have been developed for two fluoroquinolone antibacterial drugs, norfloxacin and enoxacin. Dimethylformamide (DMF) and 0.1 M hydrochloric acid were used as media for norfloxacin and enoxacin respectively. Potassium chloride was used as base electrolyte. A reduction wave was observed for norfloxacin within the range of -1.02 to -1.13 V and for enoxacin within -0.93 to -1.07 V. Linear calibration ranges for norfloxacin and enoxacin were observed within 20-100 μg/mL and 1-40 μg/mL with detection limits of 10 μg/mL and 50 ng/mL respectively. Relative standard deviations (RSD) for the analysis of 10 μg/mL norfloxacin and 10 μg/mL enoxacin (n = 5) were observed 1.1% and 0.2%. The presence of glucose, lactose, sorbitol, gum arabic, starch, magnesium stearate, methylparaben and propylparaben did not affect the determination. The methods were used for the analysis of pharmaceutical preparations and quantitative recoveries were obtained with relative deviation within 1.6-4.75%.

The sorption potential of chemically and thermally treated rice husk (RHT) for the removal of 2,4-dichlorophenol (DCP) from aqueous solutions has been investigated. Sorption of DCP by rice husk was observed over a wide pH range of 1–10. The effect of contact time between liquid and solid phases, sorbent dose, pH, concentration of sorbate and temperature on the sorption of DCP onto rice husk has been studied. The pore area and average pore diameter of RHT by BET method are calculated to be 17±0.6m2g−1 and 51.3±1.5nm, respectively. Maximum sorption (98±1.2%) was achieved for RHT from 6.1×10−5moldm−3 of sorbate solution using 0.1g of rice husk for 10min agitation time at pH 6 and 303K, which is comparable to activated carbon commercial (ACC) 96.6±1.2%, but significantly higher than chemically treated rice husk (RHCT) 65±1.6% and rice husk untreated (RHUT) 41±2.3%. The sorption data obtained at optimized conditions was subjected to Freundlich, Langmuir and Dubinin–Radushkevich (D–R) isotherms. Sorption intensity 1/n (0.31±0.01) and sorption capacity multilayer Cm (12.0±1.6mmolg−1) have been evaluated using Freundlich sorption isotherm, whereas the values of sorption capacity monolayer Q (0.96±0.03mmolg−1) and binding energy, b, (4.5±1.0)×104dm3mol−1 have been estimated by Langmuir isotherm. The Langmuir constant, b, was also used to calculate the dimensionless factor, RL, in the concentration range (0.6–6.1)×10−4moldm−3, suggesting greater sorption at low concentration. D–R sorption isotherm was employed to calculate sorption capacity Xm (2.5±0.07mmolg−1) and sorption energy E (14.7±0.13kJmol−1). Lagergren and Morris–Weber equations were employed to study kinetics of sorption process using 0.2g of RHT, 25cm3 of 0.61×10−4moldm−3 sorbate concentration at pH 6, giving values of first-order rate constant, k, and rate constant of intraparticle transport, Rid, (0.48±0.04min−1 and 6.8±0.8nmolg−1min−1/2, respectively) at 0.61×10−4moldm−3 solution concentration of DCP, 0.1g RHT, pH 6 and 2–10min of agitation time. For thermodynamic studies, sorption potential was examined over temperature range 283–323K by employing 6.1×10−4moldm−3 solution concentration of DCP, 0.1g RHT at pH 6 and 10min of agitation time and values of ΔH (−25±1kJmol−1), ΔS (−61±4Jmol−1K−1) and ΔG303K (−7.1±0.09kJmol−1) were computed. The negative values of enthalpy, entropy, and free energy suggest that the sorption is exothermic, stable, and spontaneous in nature.

The antioxidant activity of five indigenous rice bran varieties, i.e. Rice bran-Super kernel (RB-kr), Rice bran-Super 2000 (RB-s2), Rice bran-Super Basmati (RB-bm), Rice bran-Super-386 (RB-86) and Rice bran-Super fine (RB-sf), collected from the same agricultural plots, was evaluated. The order of antioxidant activity was evaluated by measurement of total phenolic content, antioxidant activity in linoleic acid system, reducing power, metal chelating ability, scavenging capacity by DPPH radical and ABTS cation radical and conjugated dienes. Determination of major antioxidant components reported in rice bran, i.e. tocopherols, tocotrienols and γ-oryzanol, was made using reverse phase HPLC. However, for comparison of tocopherol content, quantification was also done by voltammetry. The overall order of antioxidant activity was RB-kr>RB-s2>RB-bm>RB-86>RB-sf. However, according to the chelating activity and conjugated dienes assays the antioxidant efficacy of RB-sf was higher than RB-bm and RB-86. Antioxidant power was correlated with growth period and irrigation water demand by a particular variety. A strong correlation of these two parameters with antioxidant activity was observed. RB-kr has the longest growth period and takes the least amount of water out of the series and exhibits highest antioxidant activity. Strongly reverse behavior was observed in case of RB-sf.

The sorption efficiency of indigenous rice (Oryza sativa) bran for the removal of organics, that is, benzene, toluene, ethylbenzene, and cumene (BTEC), from aqueous solutions has been studied. The sorption of BTEC by rice bran is observed over a wide pH range of 1-10, indicating its high applicability to remove these organics from various industrial effluents. Rice bran effectively adsorbs BTEC of 10 microg mL(-1) sorbate concentration from water at temperatures of 283-323 +/- 2 K. The effect of pH, agitation time between solid and liquid phases, sorbent dose, its particle size, and temperature on the sorption of BTEC onto rice bran has been studied. The pore area and average pore diameter of rice bran by BET method are found to be 19 +/- 0.7 m(2) g(-1) and 52.8 +/- 1.3 nm. The rice bran exhibits appreciable sorption of the order of 85 +/- 3.5, 91 +/- 1.8, 94 +/- 1.4, and 96 +/- 1.2% for 10 microg mL(-1) concentration of benzene, toluene, ethylbenzene, and cumene, respectively, in 60 min of agitation time using 0.1 g of rice bran at pH 6 and 303 K. The sorption data follow Freundlich, Langmuir, and Dubinin-Radushkevich (D-R) models. Sorption capacities have been computed for BTEC by Freundlich (32 +/- 3, 61 +/- 14, 123 +/- 28, and 142 +/- 37 m mol g(-1)), Langmuir (6.6 +/- 0.1, 7.5 +/- 0.13, 9.5 +/- 0.22, and 9.4 +/- 0.18 m mol g(-1)), and D-R isotherms (11 +/- 0.5, 16 +/- 1.3, 30 +/- 2.2, and 33 +/- 2.5 m mol g(-1)), respectively. The Lagergren equation is employed for the kinetics of the sorption of BTEC onto rice bran and first-order rate constants (0.03 +/- 0.002, 0.04 +/- 0.003, 0.04 +/- 0.003, and 0.05 +/- 0.004 min(-1)) have been computed for BTEC at their concentration of 100 mug mL(-1) at 303 K. Studies on the variation of sorption with temperatures (283-323 K) at 100 mug mL(-1) sorbate concentration gave thermodynamic constants DeltaH (kJ mol(-1)), DeltaG (kJ mol(-1)), and DeltaS (J mol(-1) K(-1)). The results indicate that the sorption of organics onto rice bran is exothermic and spontaneous in nature under the optimized experimental conditions selected. This sorbent has been used successfully to accumulate and then to determine benzene, toluene, and ethylbenzene in wastewater sample.

A simple and reliable method has been developed using styrene-divinylbenzene-based polymeric material containing 1-nitroso-2-naphthol as chelating agent, to concentrate ultratrace amounts of Ni(II) and Cu(II) ions in aqueous samples. Sorption of both the ions on the new synthetic resin under static and dynamic conditions has been investigated. The sorption has been optimized with respect to pH, shaking and contact time of two phases. Maximum sorption has been achieved from solution of pH 5-8 after 8 min of agitation. Total saturation capacities were 516 ± 2 and 316 ± 2.5 μmol g-1 for Ni(II) and Cu(II) ions, respectively. The lowest concentration for quantitative recovery (98 ± 1%) is 1.33 and 5 ppb with the preconcentration factor of 750 and 200 for Ni(II) and Cu(II), respectively. Monitoring of the influence of diverse ions on the sorption of metal ions has revealed that phosphate, hydrogencarbonate and citrate reduce the sorption to some extent. Under optimum conditions the sorption data followed Langmuir, Freundlich, and Dubinin-Radushkevich isotherms. The kinetics and thermodynamics of sorption are studied in detail. The sorption procedure is utilized to preconcentrate these ions prior to their determination in tea, human hair, and tap water samples by atomic absorption spectrometry using direct and standard addition methods.

Copper (11) and palladium (11) were determined spectrophotometrically with sodium isoamylxanthate as complexing reagent in aqueous phase in presence of anionic/nonionic surfactant SDS/ Tween 80. Beer's law was obeyed, for Cu(II) and Pd(ll) over the range 2.0 - 30 and 2.0 - 38 mug ml(-1) respectively. The lambda(max) molar absorption, molar absorptivity and Sandell's sensitivity of Cu(ll) and Pd(ll) were 420 nm and 380 nm; epsilon(max) = ( x 10(4) mol(-1) cm(-1)) is 0.36 and 0.45 and 17.7 and 23.6 ng cm(-1) respectively. Maximum absorbance at, 1:2 (M: L) mole ratio. The complex remained stable for more than 2 h. Reagent concentration optimized 0.5% was used throughout the study. Surfactant concentration 1% SDS yields higher enhancement in absorbance of Cu(II) and 5% Tween 80 was used for maximum absorption of Pd(II) complex. The absorption maxima were obtained at optimized pH of 7.0 for all metal ions. Validation of this method has been made by comparing the results with those obtained by flame AAS, no significant difference was observed in the two methods at 95% confidence interval. The method is simple, accurate, economical and has been applied to the determination of copper(II) and palladium(II) in industrial waste samples.

An atomic absorption spectrophotometric method has been devised for the rapid determination of trace metals, found in several vegetable oils and fats. Samples were prepared using an ultrasonically assisted acid-extractive technique. The parameters of the analysis were optimized to improve the recovery of metals from the oil matrixes at an ultra trace level within the least possible time. The use of ultrasonic intensification, followed by centrifugation for phase separation reduced the conventional acid extraction time from 180 to only 10 minutes. The respective range of recovery of iron, copper, nickel and zinc was found to be 94.6-98.0 %, 93.6-100.4 %, 95.0-97.3 % and 96.0-101.2 % in a soybean oil which was fortified with 0.10, 0.25, 0.50, 0.75, 1.00 μg/gm of each of the metals using the standard addition method. The ranges of recovery of these metals as investigated by the proposed method were also found in close agreement with those of the wet digestion method. Most of the samples of commercial oils and fats were found to be contaminated with notable amounts of iron and nickel ranging from 0.13-2.48 and 0.027-2.38 ppm respectively. The contents of copper and zinc were also high in many brands, ranging from 0.01-0.15 ppm and zinc 0.03- 0.21 ppm respectively, which poses a threat to oil quality and to human health.

A micellar liquid-chromatographic method is proposed for determination of Al(III) as the 8-hydroxyquinoline-5-sulfonic acid derivative, with spectrofluorimetric detection. Cetyltrimethylammonium bromide, a cationic surfactant (0.05 M), was used as mobile phase. The metal chelate was detected at lambda(Ex)410 and lambda(Em) 510 nm. Response to aluminum is selective in the presence of other metal ions. The method eliminates the need for addition of reagent or organic modifier to the mobile phase, as is normal in RP HPLC. Under optimized conditions the linear range was 20-200 mug L-1 Al(III), the limit of detection 10 mug L-1, and the limit of quantification 40 mug L-1. The method was used to determine aluminum in a variety of water samples.

To assess the role of metal elements in the pathogenesis of human gallstones, the concentrations of some metal elements (Na, K, Ca, Mg, Mn, Cu, Fe, Pb, Ni, and Zn) in four chemically different types of human gallstones (pure cholesterol, cholesterol +calcium carbonate, cholesterol + bilirubin and calcium bilirubinate) were measured by atomic absorption spectrometry. It was observed that the concentrations of the metal elements varied greatly with the chemical nature of stone. Calcium, magnesium and manganese were found in high range of concentrations in gallstones composed of cholesterol +calcium carbonate, whereas, high concentrations for sodium, potassium, Copper, iron, lead, nickel and zinc were seen in calcium bilirubinate stones. Sexwise comparison of the data for cholesterol gallstones, showed that the levels for calcium, sodium, magnesium, manganese, iron, lead and nickel were higher in gallstones recovered from females as compared to that of males, whereas reverse was true for the concentrations of potassium and zinc. Comparison of the data for cholesterol gallstones from females of above and below 45 years age revealed no significant differences between the subjects of the two age groups. The findings of the present study may suggest that the metal elements calcium, sodium, potassium, copper, and iron do contribute towards the formation mechanism of human gallstones.

The hexane-extracted oil content of Moringa oleifera seeds ranged from 38.00 to 42.00%. Protein, fiber, and ash contents were found to be 26.50-32.00, 5.80-9.29, and, 5.60-7.50%, respectively. Results of physical and chemical parameters of the extracted oil were as follows: iodine value, 68.00-71.80; refractive index (40 degreesC), 1.4590-1.4625; density (24 degreesC), 0.9036-0.9080 mg/mL; saponification value, 180.60-190.50; unsaponifiable matter, 0.70-1.10%; and color (1 in. cell), 0.95-1.10 R + 20.00-35.30 Y. Tocopherols (alpha, gamma, and delta) in the oil were up to 123.50-161.30, 84.07-104.00, and 41.00-56.00 mg/kg, respectively. The oil was found to contain high levels of oleic acid (up to 78.59%) followed by palmitic, stearic, behenic, and arachidic acid up to levels of 7.00, 7.50, 5.99, and 4.21%, respectively. The induction period (Rancimat, 20 L/h, 120 degreesC) of the crude oil was 9.99 h and reduced to 8.63 h after degumming. Specific extinctions at 232 and 270 nm were 1.70 and 0.31, respectively. Many parameters of M. oleifera oil indigenous to Pakistan were comparable to those of typical Moringa seed oils reported in the literature. The results of the present analytical study were also compared with those of different vegetable oils.

In the present work, the rates of decomposition for Siderite and Magnesite minerals found in lignite ashes have been evaluated by isothermal thermogravimetry by monitoring the weight loss for 60 min at 350 degreesC, 400 degreesC, 500 degreesC and 575 degreesC and the mineralogical composition of coal ash was evaluated. The comparative account is also given for DTA of coal/mineral mixtures in air atmospheres which show the major exothermic effects in the initial and final temperature zones of major peak configurations.

Spectrophotometeric determination of cadmium(II), mercury(II) and manganese(II) is carried out with 1-(2 pyridylazo)-2-naphthol as complexing reagent in aqueous phase using non-ionic surfactant Tween 80. The molar absorptivity, Sandell's sensitivity, critical micelle concentration, 1-(2 pyridylazo)-2-naphthol and metal ion concentration are studied. The method has been applied to the determination of these metal ions in municipal sewerage water and pharmaceutical samples.

Seeds of Salicornia bigelovii (hybrid variety sos-10) were collected from five coastal areas of Pakistan on the Arabian Sea. Hexane-extracted oil content was 27.2-32.0%. Results of other physical and chemical parameters of the extracted oil were as follows: iodine value, 128.0-130.5; refractive index (40 degrees C), 1.4680-1.4695; unsaponifiable matter, 1.63-2.00%; saponification value, 178.6-189.0; density (30 degrees C), 0.9036-0.9074. Tocopherols (alpha, gamma, and delta) in the oil ranged up to 200 mg/kg. The S. bigelovii seed oil was found to contain high levels of linoleic acid (74.66-79.49%) and less oleic acid (12.33-16.83%). Saturated fatty acids, palmitic and stearic acids, ranged from 7 to 8.50% and from 1.24 to 1.69%, respectively. Linolenic acid (C(18:3) omega-3) was found within the range of 1.50-2.31%. The induction period (Rancimat, 20 L/h, 120 degrees C) of the crude oil was 1.40-1.70 h. Specific extinctions at 232 and 270 nm were 1.90-2.40 and 0.40-0.62, respectively. Many parameters of S. bigelovii seed oil were quite compatible with those of safflower oil.

Journal of Separation ScienceVolume 25, Issue 7 p. 462-465 Short Communication Gas chromatographic analysis of chloride, bromide, and iodide as trifluoromethylmercury(II) nitrate derivatives M. A. Arain, M. A. Arain Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro, Pakistan; Fax: +92 (0)221 771560Search for more papers by this authorM. Y. Khuhawar, M. Y. Khuhawar M.A. Kazi Institute of Chemistry, University of Sindh, Jamshoro, PakistanSearch for more papers by this authorM. I. Bhanger, M. I. Bhanger anachem@yahoo.com Search for more papers by this author M. A. Arain, M. A. Arain Center of Excellence in Analytical Chemistry, University of Sindh, Jamshoro, Pakistan; Fax: +92 (0)221 771560Search for more papers by this authorM. Y. Khuhawar, M. Y. Khuhawar M.A. Kazi Institute of Chemistry, University of Sindh, Jamshoro, PakistanSearch for more papers by this authorM. I. Bhanger, M. I. Bhanger anachem@yahoo.com Search for more papers by this author First published: 15 May 2002 https://doi.org/10.1002/1615-9314(20020501)25:7<462::AID-JSSC462>3.0.CO;2-3Citations: 2AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume25, Issue7May 2002Pages 462-465 RelatedInformation

A spectrophotometer study of zinc-dithizonate complex in aqueous phase in the presence of sodium dodecyl sulphate (SDS) anionic surfactant is reported here. The presence of micellar system avoids the previous steps of solvent extraction and reduces the Costa toxicity and enhance the molar absorptivity. The method obeys Beer's law in the concentration range of 1.5 x 10(-5) -1.5 x 10(-4) M. The detection limit of Zn(II) is 3 x 10(-6) M. The molar absorption, sensitivity, critical micelle-concentration, dithizone and metal ion concentration are studied and discussed. The method has been applied to the determination of Zn(II) in pharmaceutical preparation and vegetables. The present method was also compared with FAAS method and the results are comparable. There is no significant difference between the two methods at 95% confidence interval.