nan Sirajuddin

Evaluation of cadmium, lead, nickel and zinc status in biological samples of smokers and nonsmokers hypertensive patients

The objective of this study was to evaluate the association between trace and toxic elements zinc (Zn), cadmium (Cd), nickel (Ni) and lead (Pb) in biological samples (scalp hair, blood and urine) of smoker and nonsmoker hypertensive patients (n=457), residents of Hyderabad, Pakistan. For the purpose of comparison, the biological samples of age-matched healthy controls were selected as referents. The concentrations of trace and toxic elements were measured by atomic absorption spectrophotometer prior to microwave-assisted acid digestion. The validity and accuracy of the methodology were checked using certified reference materials and by the conventional wet acid digestion method on the same certified reference materials and real samples. The recovery of all the studied elements was found to be in the range of 97.8–99.3% in certified reference materials. The results of this study showed that the mean values of Cd, Ni and Pb were significantly higher in scalp hair, blood and urine samples of both smoker and nonsmoker patients than in referents (P<0.001), whereas the concentration of Zn was lower in the scalp hair and blood, but higher in the urine samples of hypertensive patients. The deficiency of Zn and the high exposure of toxic metals as a result of tobacco smoking may be synergistic with risk factors associated with hypertension.

Proximate Composition and Antioxidant Potential of Leaves from Three Varieties of Mulberry (Morus sp.): A Comparative Study

In this study, leaves of three indigenous varieties of Mulberry namely, Morus alba L., Morus nigra L. and Morus rubra L. were investigated for their antioxidant potential and their proximate composition was determined. The yields of 80% methanolic extracts ranged between 8.28–13.89%. The contents of total phenolics (TPC), total flavonoids (TFC) and ascorbic acid (AA) ranged between 16.21–24.37 mg gallic acid equivalent (GAE)/g, 26.41–31.28 mg rutin equivalent (RE)/g and 0.97–1.49 mg/g, respectively. The antioxidant activity of leaf extracts was evaluated by measuring 1,1-diphenyl-2-picrylhydrazyl (DPPH•) radical scavenging actity, 2,2′-azino-bis-(3-ethylbenzthiazoline-6-sulphonic acid (ABTS•+) radical cation scavenging capacity and ferric ion reducing power and values ranged between 1.89–2.12, 6.12–9.89 and 0.56–0.97 mM Trolox equivalent/g of dried leaves, respectively. The investigated features reveal good nutritive and antioxidant attributes of all the varieties with mutually significant differences.

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. Beers Law was applicable in the range of 0.07-2mugml(-1) and 0.005-0.05mugml(-1) at 245.5nm and at 262nm for aqueous standard solutions of HQ with linear regression coefficient value of 0.9978 and 0.9843 and detection limit of 0.021mugml(-1) and 0.0016mugml(-1) HQ, respectively. Standard deviation of 1.7% and 2.4% was true for 1mugml(-1) and 0.03mugml(-1) HQ solution (n=11) run at respective wavelengths. The method was successfully applied to dilute waste photographic developer samples for free HQ determination.

Evaluation of arsenic, cobalt, copper and manganese in biological Samples of Steel mill workers by electrothermal atomic absorption Spectrometry

The determination of trace and toxic elements in biological samples (blood, urine and scalp hair samples) of human beings is an important clinical test. The aim of our present study was to determine the concentration of arsenic (As), copper (Cu), cobalt (Co) and manganese (Mn), in biological samples of male production workers (PW) and quality control workers (QW) of steel mill, with aged 25–55 years, to assess the possible influence of environmental exposure. For comparison purpose, the same biological samples of unexposed healthy males of same age group were collected as control subjects. The determination of all elements in biological samples was carried out by electrothermal atomic absorption spectrometry, prior to microwave assisted acid digestion. The accuracy of the As, Cu, Co and Mn measurements was tested by simultaneously analyzing certified reference materials (CRMs) and for comparative purposes conventional wet acid digestion method was used on the same CRMs. No significant differences were observed between the analytical results and the certified values, using both methods (paired t-test at P > 0.05). The results indicate that concentrations of As, Cu, Co and Mn in all three biological samples of the exposed workers (QW and PW) were significantly higher than those of the controls. The possible correlation of these elements with the etiology of different physiological disorders is discussed. The results were also demonstrated the need of attention for improvements in workplace, ventilation and industrial hygiene practices.

l-cysteine protected copper nanoparticles as colorimetric sensor for mercuric ions

This report demonstrates a novel, simple and efficient protocol for the synthesis of copper nanoparticles in aqueous solution using L-cysteine as capping or protecting agent. UV-visible (UV-vis) spectroscopy was employed to monitor the LSPR band of L-cysteine functionalized copper nanoparticles (Cyst-Cu NPs) based on optimizing various reaction parameters. Fourier Transform Infrared (FTIR) spectroscopy provided information about the surface interaction between L-cysteine and Cu NPs. Transmission Electron Microscopy (TEM) confirmed the formation of fine spherical, uniformly distributed Cyst-Cu NPs with average size of 34 ± 2.1 nm. X-ray diffractometry (XRD) illustrated the formation of pure metallic phase crystalline Cyst-Cu NPs. As prepared Cyst-Cu NPs were tested as colorimetric sensor for determining mercuric (Hg(2+)) ions in an aqueous system. Cyst-Cu NPs demonstrated very sensitive and selective colorimetric detection of Hg(2+) ions in the range of 0.5 × 10(-6)-3.5 × 10(-6) mol L(-1) based on decrease in LSPR intensity as monitored by a UV-vis spectrophotometer. The developed sensor is simple, economic compared to those based on precious metal nanoparticles and sensitive to detect Hg(2+) ions with detection limit down to 4.3 × 10(-8) mol L(-1). The sensor developed in this work has a high potential for rapid and on-site detection of Hg(2+) ions. The sensor was successfully applied for assessment of Hg(2+) ions in real water samples collected from various locations of the Sindh River.

Glycine-assisted synthesis of NiO hollow cage-like nanostructures for sensitive non-enzymatic glucose sensing

In this work, a highly sensitive non-enzymatic glucose sensor was developed based on NiO hollow cage-like nanostructures (NiO HCs). The novel nanostructures were synthesized using hydrothermal growth route with glycine employed as an effecient growth director. The synthesized NiO HCs were characterized by using scanning electron microscopy (SEM), X-ray photoelectron microscopy (XPS) X-ray diffraction (XRD) and Fourier transform infrared (FTIR) techniques for morphological, compositional and structural determination respectively. The prepared NiO HCs were directly integrated to be structured electrodes exhibiting enhanced electrocatalytic performance toward the oxidation of glucose with high sensitivity (2476.4 μA mM−1 cm−2), low detection limit (LOD) (0.1 μM), wide detection range (0.1–5.0 mM) (r2 = 0.9997) and excellent reproducibility. The developed non-enzymatic glucose sensor further demonstrated excellent anti-interference property in the presence of common interferents such as uric acid (UA), dopamine (DP) and ascorbic acid (AS). The role of glycine molecules as an efficient growth directing agent with a plausible growth mechanism has also been highlighted. In addition, the NiO HCs modified electrode was also used to analyze glucose concentration in human serum samples. The excellent sensing performance can be attributed to the unique morphology, which allowed increased electron transfer passages with lower charge transfer resistance, and enhanced molecular approach during electrochemical sensing offered from nanoscale “hollow cage” units of NiO structures.

Effect of zinc supplementation on the zinc level in serum and urine and their relation to thyroid hormone profile in male and female goitrous patients

BACKGROUND & AIMSnZinc (Zn) is an essential element involved in many basic biochemical reactions in thyroid. The aims of present study is to evaluate the Zn status in biological samples and thyroid hormones levels in 60 goitrous male (GMPs) and 72 female patients (GFPs), before and after 6 months treatment with Zn supplementation and compared with non-goitrous subjects of both genders (M=106, F=120) of age range 16-30 years.nnnMETHODSnThe biological samples were analyzed for Zn concentration using flame atomic absorption spectrophotometer, following their microwave assisted acid digestion. Quality control for the methodology was established with certified samples and with those obtained by conventional wet acid digestion method on the same CRMs and real samples.nnnRESULTSnThe results showed that the significantly lower mean values of Zn in serum, while high level urine samples of GMPs and GFPs were observed as compared to control subjects (p<0.005 and 0.007) respectively. The mean values of free triiodothyronine and thyroxin were found to be lower in goitrous patients of both genders than in the age matched healthy control (p<0.006 and 0.002) respectively, in contrast high mean values of thyroid stimulating hormone were detected in GMPs and GFPs (p<0.009).nnnCONCLUSIONnIt was observed that Zn status and serum thyroid hormone levels were improved in goitrous patients after six months treatment with Zn supplementation.

Ultra-fast catalytic reduction of dyes by ionic liquid recoverable and reusable mefenamic acid derived gold nanoparticles.

We synthesized mefenamic acid (MA) derived gold nanoparticles (MA-AuNps) in aqueous solution (MA-Au sol). Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) of the sol at 1, 5, 15 and 60 min showed changes in size and shape of formed AuNps. Fourier Transform Infrared (FTIR) Spectroscopy revealed the interaction between AuNps and MA. Each Au sol exhibited exceptional catalytic activity for the reduction of Methylene Blue (MB), Rose Bengal (RB) and Eosin B (EB) dye individually as well as collectively. However, complete reduction of dye(s) was accomplished by Au sol of 5 min in just 15s. The catalytic performance of Ma-Au sol was far superior to that adsorbed on glass. AuNps were recovered with the help of water insoluble room temperature ionic liquid and reused with enhanced catalytic potential. This finding is a novel, rapid and highly economical alternative for environmental safety against pollution by dyes and extendable for control of other reducible contaminants as well.

Green Chemical Synthesis of Silver Nanoparticles and its Catalytic Activity

Silver nanoparticles (Ag(0) NPs) were synthesized by the chemical reduction method, in which ceftriaxone (antibiotic) used as reducing (to convert Ag+ to Ag(0)) and capping agent. UV–Visible spectroscopy revealed the first indication of formation of Ag(0) NPs. FT-IR spectroscopy showed the interaction of formation of bonding between antibiotic standard and silver. X-ray powder diffraction powder pattern confirmed the crystalline nature of prepared Ag(0) NPs. These Ag(0) NPs were used as catalyst for three organic hazardous chemicals i.e., 4-nitro-1,3-Phenylene diamine, 6-methyl-2-nitroanilline, 4-methyle-2-nitroanilline. The prepared Ag(0) NPs showed good catalytic activity against these compounds.

Controlled synthesis and electrochemical application of skein-shaped NiO nanostructures

AbstractA simple, economical and mild solution chemistry method was used to synthesize diverse nickel oxide (NiO) nanostructures employing methionine as a growth-directing agent. The as-synthesized NiO nanostructures were observed to possess a unique skein-shape morphology with uniform spherical distribution. The NiO nanoskein (NiO NSk) formation was extensively studied using X-ray diffraction (XRD), X-ray photoelectron microscopy (XPS), scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) techniques, respectively. The unique NiO NSks exhibited better electrocatalytic activity towards glucose oxidation in alkaline media, enabling the development of a highly sensitive non-enzymatic glucose sensor. The observed analytical properties included high sensitivity (1915xa0μAxa0mM−1xa0cm−2), wide linear range (0.1–5.0xa0mM), low detection limit (0.7xa0μM), higher stability and reproducibility. Moreover, the sensor is selective in the presence of interfering species such as ascorbic acid (AA), uric acid (UA) and dopamine (DP) during the non-enzymatic glucose sensing. The worthy-of-notice electrocatalytic activity and economical feasible preparation of NiO NSk-shaped electroactive material for direct glucose-sensing applications make the present study of high interest for the fabrication of low-cost devices. A NiO NSk-based glucose sensor has also been employed for glucose determination in human serum with adequate results, suggesting high potential for the routine monitoring of glucose from biotechnology, clinical and food industry samples.n Graphical abstractGraphical representation of NiO NSks formation