Abdul Haleem Panhwar

Simultaneous preconcentration of toxic elements in artificial saliva extract of smokeless tobacco product, mainpuri by cloud point extraction method.

It has been extensively investigated that smokeless tobacco chewing can lead mainly to inflammation of oral cavity. In present study, the total and artificial saliva extracted toxic elements, arsenic, cadmium, nickel and lead were estimated in smokeless tobacco product, mainpuri. Cloud point extraction has been used for the preconcentration of arsenic, cadmium, nickel and lead in artificial saliva extract, using complexing reagent, ammonium pyrrolidinedithiocarbamate. Total and extractable toxic elements were measured by electrothermal atomic absorption spectrometry. The chemical variables of cloud point extraction were optimized. The validity of methodology was tested by simultaneously analyzing certified reference material (Virginia tobacco leaves) and spike recovery test. The artificial saliva extractable levels of arsenic, cadmium, nickel and lead ranged from 15-22, 45-70, 35-58, and 18-32%, respectively, of total elemental contents in mainpuri samples. It was estimated that intake of 10g of different brands of mainpuri contributing the 5.88, 55.0, 45.0 and 40.3% of the provisional maximum tolerable daily intake for arsenic, cadmium, nickel and lead, respectively for adults of ~60kg.

A new solid phase microextraction method using organic ligand in micropipette tip syringe system packed with modified carbon cloth for preconcentration of cadmium in drinking water and blood samples of kidney failure patients

A simple and efficient miniaturized solid phase microextraction (M-SPμE) in a syringe system was developed for preconcentration of cadmium (Cd) in environmental and biological samples, followed by flame atomic absorption technique. The syringe system contains the micropipette tip packed with activated carbon cloth, coated with modified magnetic nanoparticles of iron oxide Triton X114 (ACC-NPs). Scanning electron microscopy and energy dispersive spectroscopy used for characterization of the size, morphology and elemental composition of ACC-NPs. The sample solution treated with a complexing reagent 8-hydroxyqunilone (8-HQ), and drawn into the syringe, filled with ACC-MNPs and dispensed manually for 2-10 drawing/discharging cycles. The analyte retained on ACC-NPs in micropipette tip-syringe system were then eluted with different volume of 1.5molL(-1) HCl by 1-5 drawing/discharging cycles. The syringe system directly couple with FAAS for analysis. The influence of different variables on the extraction efficiency of Cd, including adsorbent dosage, pH, sample volume, eluent volume and drawing/discharging cycles of syringe system were optimized. At optimized extraction conditions, the method showed good linearity in the range of 5-250μgL(-1), with a limit of detection 0.15μgL(-1). Repeatability of the extraction (%RSD) was <5%, n=5. The validity and accuracy of the method was checked by the certified reference materials. The proposed method was successfully applied for the determination of Cd in different drinking water and biological samples of kidney failure patients and healthy controls.

Application of dual-cloud point extraction for the trace levels of copper in serum of different viral hepatitis patients by flame atomic absorption spectrometry: a multivariate study.

An efficient, innovative preconcentration method, dual-cloud point extraction (d-CPE) has been developed for the extraction and preconcentration of copper (Cu(2+)) in serum samples of different viral hepatitis patients prior to couple with flame atomic absorption spectrometry (FAAS). The d-CPE procedure was based on forming complexes of elemental ions with complexing reagent 1-(2-pyridylazo)-2-naphthol (PAN), and subsequent entrapping the complexes in nonionic surfactant (Triton X-114). Then the surfactant rich phase containing the metal complexes was treated with aqueous nitric acid solution, and metal ions were back extracted into the aqueous phase, as second cloud point extraction stage, and finally determined by flame atomic absorption spectrometry using conventional nebulization. The multivariate strategy was applied to estimate the optimum values of experimental variables for the recovery of Cu(2+) using d-CPE. In optimum experimental conditions, the limit of detection and the enrichment factor were 0.046μgL(-1) and 78, respectively. The validity and accuracy of proposed method were checked by analysis of Cu(2+) in certified sample of serum (CRM) by d-CPE and conventional CPE procedure on same CRM. The proposed method was successfully applied to the determination of Cu(2+) in serum samples of different viral hepatitis patients and healthy controls.

Exposure of children to arsenic in drinking water in the Tharparkar region of Sindh, Pakistan

Humans can be exposed to arsenic (As) through air, drinking water, and food. The aim of this study was to calculate the hazard quotient (HQ) of As, based on its concentration in drinking water and the scalp hair of children (males) belonging to two age groups (5-10 and 11-14 years) who consumed water contaminated with different concentrations of As. The water samples were collected from As-exposed and nonexposed areas, which were classified as low-exposed (LE), high-exposed (HE), and nonexposed (NE) areas. The total concentration of inorganic As (iAs) and its species (As(III) and As(V)) in water samples of all selected areas was determined by advanced extraction methods. For purposes of comparison, the total As level was also determined in all water samples. The resulting data indicated that the predominant inorganic As species in groundwater samples was arsenate (As(V)). The As concentrations in drinking water of LE and HE areas were found to be 2.6-230-fold higher than the permissible limit for drinking water established by the World Health Organization (2004). However, the As levels in drinking water of the NE area was within the permissible limit (<10 μg/L). The As levels in the scalp hair samples from boys of NE, LE, and HE areas ranged from 0.16 to 0.36, 0.36 to 0.83, and 11.5 to 31.9 mg/kg, respectively. A significant, positive correlation was observed between the As levels in drinking water and scalp hair samples of children from the HE area, compared with the other two groups (p>0.01). The As toxicity risk assessment based on HQ for the NE, LE, and HE areas corresponded to <10, ≥ 10, and >10, respectively. These HQ values indicated the noncarcinogenic, less carcinogenic, and highly carcinogenic exposure risks faced by children from the NE, LE, and HE areas, respectively. It can be concluded that children consuming the groundwater of the LE (Khairpur Mirs) and HE (Tharparkar) areas of Pakistan are at a potential risk of chronic As toxicity.

A new dispersive liquid–liquid microextraction using ionic liquid based microemulsion coupled with cloud point extraction for determination of copper in serum and water samples

A simple and rapid dispersive liquid-liquid microextraction procedure based on ionic liquid assisted microemulsion (IL-µE-DLLME) combined with cloud point extraction has been developed for preconcentration copper (Cu(2+)) in drinking water and serum samples of adolescent female hepatitits C (HCV) patients. In this method a ternary system was developed to form microemulsion (µE) by phase inversion method (PIM), using ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate ([C4mim][PF6]) and nonionic surfactant, TX-100 (as a stabilizer in aqueous media). The Ionic liquid microemulsion (IL-µE) was evaluated through visual assessment, optical light microscope and spectrophotometrically. The Cu(2+) in real water and aqueous acid digested serum samples were complexed with 8-hydroxyquinoline (oxine) and extracted into IL-µE medium. The phase separation of stable IL-µE was carried out by the micellar cloud point extraction approach. The influence of of different parameters such as pH, oxine concentration, centrifugation time and rate were investigated. At optimized experimental conditions, the limit of detection and enhancement factor were found to be 0.132 µg/L and 70 respectively, with relative standard deviation <5%. In order to validate the developed method, certified reference materials (SLRS-4 Riverine water) and human serum (Sero-M10181) were analyzed. The resulting data indicated a non-significant difference in obtained and certified values of Cu(2+). The developed procedure was successfully applied for the preconcentration and determination of trace levels of Cu(2+) in environmental and biological samples.

Solid phase microextraction of trace levels of copper in serum samples of hepatitis B patients, on activated carbon cloth modified with an ionic liquid by using a syringe mountable filter technique

A simple, inexpensive and miniaturized solid phase microextraction method using a syringe mountable filter as a substitute for batch and column techniques was developed for rapid extraction and determination of copper ions (Cu2+). Activated carbon cloth (ACC), modified with the ionic liquid (IL), 1-butyl-3-methylimidazolium hexafluorophosphate [C4MIM][PF6], was used as sorbent. The modified ACC was packed on mountable membrane filter in a plastic syringe system. The surface modification, elemental composition and characterization of ACC were confirmed using scanning electron microscopy, energy dispersive X-ray spectroscopy and Fourier-transform infrared spectroscopy. The sample solution treated with a complexing reagent, ammonium pyrrolidine dithiocarbamate, was drawn into the syringe filled with IL-ACC and dispensed manually. Then the Cu2+ complex sorbed on the IL-ACC was quantitatively eluted by drawing and dispensing of different concentrations of acids. The influence of different variables on the extraction efficiency, including the concentration of ligand, pH, sample volume, eluent type, concentration and volume, and interfering ions was investigated using flame atomic absorption spectrometry. In order to validate the developed method, a certified reference material (CRM) of human serum (Sero-M10181®) was analyzed, which indicated a non-significant difference in the experimental and certified values. The proposed method was successfully applied for the determination of Cu2+ in serum samples of hepatitis B patients and healthy controls.

Preconcentration and determination of manganese in biological samples by dual-cloud point extraction coupled with flame atomic absorption spectrometry

An efficient, innovative preconcentration method using dual-cloud point extraction (d-CPE) was developed for the analysis of trace levels of manganese (Mn2+) in biological samples (scalp hair) prior to coupling with flame atomic absorption spectrometry (FAAS). In the first step of d-CPE, Mn2+ was complexed with 1-(2-pyridylazo)-2-naphthol (PAN), which was subsequently entrapped in a nonionic surfactant (Triton X-114). In the second step, the entrapped metal complex in the surfactant-rich phase was treated with aqueous nitric acid solution and heated; the studied metal ions were back-extracted again into aqueous phase. The aqueous phase was subjected to FAAS using conventional nebulization. The validity of the proposed method was verified by the analysis of Mn2+ in a certified sample of scalp hair (CRM) by both d-CPE and conventional CPE procedures. The enhancement factor of Mn2+ was found to be 46. The proposed method was successfully applied to the determination of Mn2+ in acid-digested scalp hair samples of Parkinsons patients and healthy referents.

Comparative evaluation of essential and toxic elements in the blood of kidney failure patients and healthy referents

The aim of the present study was to evaluate the comparative distribution, correlation, and apportionment of selected elements—aluminum (Al), calcium (Ca), cadmium (Cd), potassium (K), magnesium (Mg), sodium (Na), and lead (Pb)—in the blood samples of male kidney failure patients (KFP) and healthy subjects of age ranged 30–60 years. The blood samples were digested with nitric acid and perchloric acid mixture (2:1), followed by the quantification of elements by atomic absorption spectrometry. The concentration of essential elements in blood samples of KFP were found in the range of Ca (97–125), Mg (18–36), Na (2971–3685), and K (177–270) mg/L while, the levels of Al, Cd, and Pb were found in the range of (475–1275), (0.9–9.9), and (211–623) μg/L, respectively. In the healthy referents, concentration of electrolytes in blood samples was lower than KFP, but difference was not significant (p > 0.05). While the levels of toxic elements in blood samples of referents were three- to sixfold lower than KFP (p < 0.01). Principal component analysis (PCA) and cluster analysis (CA) of the element data manifested diverse apportionment of the selected elements in the blood sample of the KFP compared with the healthy counterparts.

Investigation of Alteration in the Levels of Iron and Copper in Scalp Hair Samples of Patients Having Different Types of Viral Hepatitis

The aim of this study was to measure the alterations of copper and iron contents in scalp hair samples of hepatitis A–E patients of both genders, same age group, and socioeconomic status. For comparative study, the scalp hair samples of healthy individuals of the same age and socioeconomic status were collected. The concentrations of copper and iron were measured using an atomic absorption spectrophotometer, after microwave-assisted acid digestion. The validity and accuracy of methodology was checked using a certified reference material. The results of this study showed that the mean values of copper and iron were higher in scalp hair samples of hepatitis patients than those of age-matched control subjects, while the difference was significant in the cases of patients having viral hepatitis B, C, and D as compared to those who have viral hepatitis A and E (p < 0.001). It was concluded that the overload of copper and iron in the human body may cause lipid peroxidation and eventually damage the hepatic system.

Determination of trace levels of iron in serum samples of hepatitis B and C patients using dispersive liquid–liquid microextraction

An environmentally friendly ionic liquid-based dispersive liquid–liquid microextraction (IL-DLLμE) method was developed for the preconcentration of trace levels of iron (Fe) in serum samples of hepatitis B and C patients, prior to its determination by flame atomic absorption spectrometry. The procedure was based on complexation of iron with a chelating reagent, 8-hydroxyquinoline (oxine), whereas an ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate [C4MIM][PF6], and ethanol were chosen as extracting and dispersive solvents, respectively. The factors affecting the efficiency of IL-DLLμE, such as the amount of IL, pH, centrifugation time and ligand concentration, were investigated in detail. The resulting data indicated that the coexisting cations and anions ions had no apparent influence on determination of Fe at trace levels. Under optimal experimental conditions, the enhancement factor and the limit of detection were 59.1 and 1.29 μg L−1, respectively. The relative standard deviation for five replicate determinations of Fe at 50 μg L−1 was calculated to be <5.0%. The developed method was validated by determining Fe in a certified reference material of serum. The proposed method can be successfully used for the enrichment of Fe in acid digested serum samples of female hepatitis B and C patients.