Naeem Ullah

Evaluation of high levels of fluoride, arsenic species and other physicochemical parameters in underground water of two sub districts of Tharparkar, Pakistan: A multivariate study

In present study total arsenic, inorganic arsenic species and fluoride ion contaminations in underground water of Diplo and Chachro sub district of Tharparkar, Pakistan were investigated. The concentrations of total As, inorganic As species, F(-) and others physicochemical parameters were reported in terms of basic statistical parameters, principal component analysis, cluster analysis, sodium absorption ratio and saturation indices. The As(3+) was determined by cloud point extraction using ammonium pyrrolidinedithiocarbamate (APDC) as complexing reagent, and complex was 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 HNO(3) in methanol. While total inorganic arsenic (iAs) was determined by solid phase extraction using titanium dioxide (TiO(2)) as an adsorbent, after centrifugation, the solid phase was prepared to be slurry for determination. The extracted As species were determined by electrothermal atomic absorption spectrometry. The concentration of As(5+) in the water samples was calculated by the difference of the total iAs and As(3+), while F(-) and other anions were determined by ion chromatography. The positive correlation of F(-) and As species with Na(+) and HCO(3)(-) showed that the water with high salinity and alkalinity stabilized the As species and F(-) in the groundwater. The positive correlation (r = 0.640, p = 0.671) was observed between total As and it species with F(-). Results showed that underground water samples of these two areas of Tharparkar were severely contaminated with arsenic and fluoride ion, which are exceeded the World Health Organization (WHO) provisional guideline value, and United States Environmental Protection Agency, maximum contaminant level of 0.01 mg/L and 1.5 mg/L, respectively.

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.

Application of ultrasonically modified cloud point extraction method for simultaneous enrichment of cadmium and lead in sera of different types of gallstone patients

A novel and greener ultrasonically assisted/modified cloud point extraction procedure for the simultaneous preconcentration of lead and cadmium in serum samples of different types of gallstone patients was developed. The chelates of the under study metals, formerly formed with 8-hydroxyquinoline, were extracted in the micelles of a nonionic surfactant prior to analysis by flame atomic absorption spectrometer (FAAS). After the arrival of the cloud point, the critical micellar mass produced was homogenously dispersed in the aqueous phase with the help of ultrasound energy. The reliability of the developed procedure was tested by relative standard deviation (% RSD), which was found to be <5%. The performance of the proposed procedure was checked by applying to certified reference material and spiking standard in real samples. All the experimental parameters were optimized. The developed procedure of Um-CPE was applied successfully for the analysis of the target heavy metals in serum samples of different types of gallstone patients and referents. The higher levels of the understudy metals were observed in the patients as compared to the referents but the levels of the both metal were found to be considerably higher in patients with pigmented gallstones.

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.

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.

Preservation of ready to serve blended carrot and kinnow (mandarin) drink by ginger extract.

This study explore the effect of lemon and ginger extract on carrot and kinnow blended ready to serve (RTS) drinks during three months refrigeration temperature storage. The treatments were CKG0,CKG1,CKG2,CKG3,CKG4,CKG5 and CKG6 having 0.5 liter carrot juice, 0.5 liter kinnow juice, 1 g/kg CMC, 1 kg sugar, 5 liter water with variations in lemon and ginger extract in different levels. All the RTS samples were evaluated for total solids, moisture, ash, pH, reducing sugar, ascorbic acid, non-reducing sugar, titratble acidy, total soluble solids, total microbial count and sensory attribute (taste, colour, flavor and overall acceptability). Statistical analysis revealed that treatment as well as storage had significant (p<0.05) effect on physicochemical and sensory properties. Results showed that pH and sugar acid ration of the treated samples was decrease during storage. While TSS, acidity, reducing and non-reducing sugar and vitamin C increased were observed during storage. Generally this is observed from the results that CKG6 sample was more acceptable than RTS of the samples on the basis of physiochemically. On the other hand, in terms of taste and flavor CKG6 sample was highly acceptable, sample CKG3 had good color and over all acceptability. However, RTS drinks prepared from with carrot and kinnow blends (CKG6) is recommended for commercial use and for production on large scale.

Development of miniaturized solid phase microextraction of copper in serum using a micropipette tip in-syringe system combined with micro sampling flame atomic absorption spectrometry

A new miniaturized solid phase microextraction (SPmE) method, using a micropipette tip, packed with carbon cloth, mounted on a syringe, was developed for preconcentration and determination of trace levels of copper in serum samples of male adolescents having hepatitis C. For comparative purposes healthy boys of the same age group (12–15 years), socioeconomic status and residential areas were also selected. The sample solution was treated with a complexing reagent 8-hydroxyquinoline (oxine), drawn into the syringe fitted with an ACC filled micropipette tip and dispensed manually for 2–10 drawing/discharging cycles. The analytes retained on ACC in a micropipette tip-syringe system were eluted with different volumes (50–200 μL) of 2 mol L−1 HNO3 in ethanol by 1–5 drawing/dispensing cycles. The influence of different analytical parameters (amount of ACC, oxine concentration, sample volume, pH, drawing and dispensing cycles, type and volume of eluent) was investigated to optimize the developed method. The developed method showed a linear response for standards of Cu, over the concentration range of 5–75 μg L−1 with correlation coefficients (R2) ≥0.997. Under the optimized experimental variables, the enhancement factors and limits of detection (LODs) were obtained to be 56 and 0.36 μg L−1, respectively, with a relative standard deviation of ≤5%. The validity and accuracy of the developed method were checked using the matrix matched certified reference material of human serum (Sero-M10181). The method was successfully applied for the preconcentration and determination of trace levels of Cu2+ in serum samples of adolescent male HCV patients and healthy controls of the same age group.

High Gain Observer Design for Eth Helicopter

This paper deals with the design of a high gain observer (HGO) for the ETH helicopter laboratory process. The standard format of high gain observer is used and the parameters of the observer are selected in such away that the observer gain matrix H0 becomes Hurwitz. The observer not only estimates the angular positions and velocities of the system but also rejects the disturbance and the measurement noise. The simulation results show the effectiveness of the HGO