Voltammetric determination of nitrite by using a multiwalled carbon nanotube paste electrode modified with chitosan-functionalized silver nanoparticles.

A cyclic voltammetric method is described for the determination of nitrite by using a multiwalled carbon nanotube paste electrode (MWCNT) that was modified with chitosan-functionalized silver nanoparticles (Chit-AgNPs). The AgNPs were prepared by one step procedure using chitosan as stabilizing agent. The resulting modified AgNPs were drop-coated onto the electrode.

Nonenzymatic amperometric dopamine sensor based on a carbon ceramic electrode of type SiO/C modified with CoO nanoparticles.

An amperometric nonenzymatic dopamine sensor has been developed. Cobalt oxide (CoO) nanoparticles were uniformly dispersed inside mesoporous SiO/C. A sol-gel process was used for the preparation of this mesoporous composite material (SiO/C).

Simultaneous assessment of zinc, cadmium, lead and copper in poultry feeds by differential pulse anodic stripping voltammetry.

In the present work four metals (Zn, Cd, Pb and Cu) were determined simultaneously in 28 commercial broiler poultry feeds by differential pulse anodic stripping voltammetry (DPASV) using hanging mercury drop electrode (HMDE). The digestion of poultry feeds was carried out with concentrated nitric acid and hydrogen peroxide (2:1) with the help of microwave heating. Acetate buffer of pH 5 was used as a supporting electrolyte.

The correlation of arsenic levels in drinking water with the biological samples of skin disorders.

Arsenic (As) poisoning has become a worldwide public health concern. The skin is quite sensitive to As and skin lesions are the most common and earliest nonmalignant effects associated to chronic As exposure. In 2005-2007, a survey was carried out on surface and groundwater arsenic contamination and relationships between As exposure via the drinking water and related adverse health effects (melanosis and keratosis) on villagers resides on the banks of Manchar lake, southern part of Sindh, Pakistan.

A new simple sensitive differential pulse polarographic method for the determination of acrylamide in aqueous solution.

A new simple sensitive differential pulse polarographic (DPP) method was investigated for the determination of acrylamide (AA) directly in a neutral aqueous solution. The AA showed a well-defined and well-resolved peak in pure aqueous LiCl at -1.84V in the potential range from -1.

Ultra-trace level determination of hydroquinone in waste photographic solutions by UV-vis spectrophotometry.

A simpler UV-vis spectrophotometric method was investigated for hydroquinone (HQ) determination using KMnO(4) as oxidizing agent for conversion of HQ to p-benzoquinone (BQ) as well as signal enhancer. Various parameters such as analytical wavelength, stability time, temperature, pH, solvent effect and interference of chemicals were checked and parameters optimized by using 1mugml(-1) standard solution of HQ. Beer's Law was applicable in the range of 0.

Electrolytic recovery of chromium salts from tannery wastewater.

Tannery wastewater collected from a local leather industry in Peshawar, Pakistan was subjected to DC electrolysis in a simple cell having two static sheet electrodes and stirring assembly after proper dilution and adjustment to desired conditions. One percent HNO(3) and 1% NaHCO(3) were used as electrolytes and pH adjusters. The latter salt also worked as sodium source for anodic deposition of Na(2)Cr(2)O(7).

Simpler spectrophotometric assay of paracetamol in tablets and urine samples.

A very fast, economical and simpler direct spectrophotometric method was investigated for paracetamol (PC) determination in aqueous medium without using any chemical reagents. The method is based on the photo-absorption of the analyte at 243 nm after dissolution in water. The change in structure of PC after addition of water was studied by comparing the corresponding FTIR spectra.