Nasreen Ghazi Ansari

Optimization and Validation of an Extraction Method for the Analysis of Polycyclic Aromatic Hydrocarbons in Chocolate Candies

UNLABELLED Chocolate is a key ingredient in many foods such as milk shakes, candies, bars, cookies, and cereals. Chocolate candies are often consumed by mankind of all age groups. The presence of polycyclic aromatic hydrocarbons (PAHs) in chocolate candies may result in health risk to people. A rapid, precise, and economic extraction method was optimized and validated for the simultaneous determination of polycyclic aromatic hydrocarbons in chocolate candy by high-performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GS-MS) as a confirmatory technique. The method was optimized by using different solvents for liquid-liquid extraction, varying volume of de-emulsifying agent, and quantity of silica gel used for purification. The HPLC separation of 16 PAHs was carried out by C-18 column with mobile phase composed of acetonitrile : water (70 : 30) in isocratic mode with runtime of 20 min. Limit of detection, limit of quantification (LOQ), and correlation coefficients were found in the range of 0.3 to 4 ng g⁻¹, 0.9 to 12 ng g⁻¹, and 0.9109 to 0.9952, respectively. The exploration of 25 local chocolate candy samples for the presence of PAHs showed the mean content of benzo[a]pyrene as 1.62 ng g⁻¹, which representing the need to evaluate effective measures to prevent more severe PAHs contamination in chocolate candies in future. PRACTICAL APPLICATION Chocolate is one of the most favorite food items among people, especially children. Chocolate candies are often consumed by mankind of all age groups. Chocolate candies are often consumed by children in large quantities. The presence PAHs in chocolate candies may result in health risk to people. In the present study, a precise and cost effective rapid method was employed for the determination of PAHs, which can be employed for daily routine analysis of PAHs in chocolate products.

Developmental Exposure to As, Cd, and Pb Mixture Diminishes Skeletal Growth and Causes Osteopenia at Maturity via Osteoblast and Chondrocyte Malfunctioning in Female Rats

We studied the effect of metal mixture (MM), comprising As, Cd, and Pb, in developing female rat skeleton from gestation day 5 until postnatal day 60 (P-60). MM resulted in synergistic inhibition in viability and differentiation of osteoblasts in vitro, likely induced by reactive oxygen species. MM, administered at their most frequently occurring concentrations present in the groundwater of India, i.e., As: 0.38 ppm, Pb: 0.22 ppm, and Cd: 0.098 ppm or 10× of the ratio to developing rats, exhibited a synergistic decrease in ex vivo mineralization of bone marrow stromal (osteoprogenitor) cells. MM group showed a dose-dependent attenuation in weight and axial lengths and shortening of tibias at P-60. Furthermore, the growth plate was shortened, which was associated with shorter proliferative and hypertrophic zones, decreased parathyroid hormone-related protein and Indian hedgehog expression in the chondrocytes, reduced primary and secondary spongiosa, and hypomineralized osteoids-a major characteristic of osteomalacia. In addition, compared with the control, MM-treated rats were clearly osteopenic based on bone mineral density, microarchitecture, biomechanical strength, and particularly the biochemical profile, that suggested high turnover bone loss. Finally, in comparison to the control, the fracture-healing ability of MM group was delayed and accompanied by inferior quality of the healed bone. Together, these data demonstrated that the mixture of As, Cd, and Pb induced synergistic toxicity to developing skeleton, thereby diminishing modeling-directed bone accrual, inducing osteopenia and dampening fracture healing.

A comprehensive toxicity study of zinc oxide nanoparticles versus their bulk in Wistar rats Toxicity study of zinc oxide nanoparticles

The purpose of this study was to characterize the zinc oxide nanoparticles (ZnO-NPs) and their bulk counterpart in suspensions and to access the impact of their acute oral toxicity at doses of 300 and 2000 mg/kg in healthy female Wistar rats. The hematological, biochemical, and urine parameters were accessed at 24 and 48 h and 14 days posttreatment. The histopathological evaluations of tissues were also performed. The distribution of zinc content in liver, kidney, spleen, plasma, and excretory materials (feces and urine) at 24 and 48 h and 14 days posttreatment were accessed after a single exposure at dose of 2000 mg/kg body weight. The elevated level of alanine amino transferase, alkaline phosphatase, lactate dehydrogenase, and creatinine were observed in ZnO-NPs at a dose of 2000 mg/kg at all time points. There was a decrease in iron levels in all the treated groups at 24 h posttreatment as compared to control groups but returned to their normal level at 14 days posttreatment. The hematological parameters red blood cells, hemoglobin, hematocrit, platelets, and haptoglobin were reduced at 48 h posttreatment at a dose of 2000 mg/kg ZnO-NPs and showed hemolytic condition. All the treated groups were comparable to control group at the end of 14 days posttreatment. The zinc concentration in the kidney, liver, plasma, feces, and urine showed a significant increase in both groups as compared to control. This study explained that ZnO-NPs produced more toxicological effect as compared to their bulk particles as evidenced through alteration in some hemato-biochemical parameters and with few histopathological lesions in liver and kidney tissues.

Fast agitated directly suspended droplet microextraction technique for the rapid analysis of eighteen organophosphorus pesticides in human blood

A new sample preparation technique named as fast agitated directly suspended droplet microextraction (FA-DSDME) was proposed as an improved version of directly suspended droplet microextraction (DSDME) for the extraction and pre-concentration of wide-range organophosphorus pesticides (OPPs) from human blood prior to liquid chromatography tandem mass spectrometric (LC-MS/MS) analysis. In this method, instead of protecting the unwanted rupturing of extraction droplet (organic solvent), it was deliberately splintered into fine droplets by providing automated high-speed agitation to the biphasic extraction system (extraction solvent and sample solution). Fine organic droplets were then recollected into one, not by using a centrifuge machine but just by giving a very slow stirring to the bottom of the extraction system. The present method has surmounted the problem of prolonged extraction time associated with old DSDME. Under optimum extraction conditions, the method showed good sensitivity with low detection limits ranging from 0.0009 to 0.122μgL(-1). Mean recoveries were achieved in the range of 86-109% at three levels of spiking concentration (low, middle and high) from linearity range of individual analyte. Intra-day and inter-day precisions were ≤4.68 and ≤9.57 (%RSD) respectively. Enrichment factor (EF) for each analyte varied from 30 to 132 which prove the ability of this technique to pre-concentrate the extracted analytes up to a good extent. The sample matrices have shown an insignificant influence on methods sensitivity. The proposed method may find immense use in epidemiological, toxicological, regulatory and forensic laboratories.

Solid phase micro extraction combined with gas chromatography-mass spectrometry for the trace analysis of polycyclic aromatic hydrocarbons in chocolate

A brisk, lucrative, sensitive and reliable Solid Phase Micro Extraction (SPME) method combined with Gas Chromatography-Mass Spectrometry (GC-MS) is developed for the simultaneous trace level determination of 16 Polycyclic Aromatic Hydrocarbons (PAHs) in chocolate samples. Various parameters such as extraction temperature, extraction time, stirring speed, ionic strength or salting out effect, pH effect, desorption temperature and time that can affect the extraction efficiency were thoroughly studied. The sensitivity of the proposed method was evaluated and compared with that of Gas Chromatography-Flame Ionisation Detection (GC-FID) and GC-MS in both the full scan acquisition and selected ion monitoring (SIM) mode. The detection (S/N = 3) and quantification limits (S/N = 10) for GC with FID, MS in full scan acquisition and in SIM mode were found to be in the range of 0.1–3.3 ng g−1, 0.04–1.11 ng g−1, 0.004–0.44 ng g−1 and 0.3–11 ng g−1, 0.13–3.69 ng g−1, 0.01–1.46 ng g−1 respectively. The method showed good linearity behavior with coefficients of correlation (R2) ranging between 0.991–0.998, 0.989–0.998 and 0.991–0.999 for GC with FID, MS in full scan acquisition and SIM mode, respectively. The method was validated by its application to the determination of 16 PAHs in spiked chocolate samples. Average recoveries were found to vary between 84.7 and 105% for individual PAH at three spiked concentration levels, which illustrates that the optimized method was not greatly affected by the sample matrix for the determination of 16 PAHs. Moreover, the presented method that combines the advantage of SPME with GC has high sensitivity and can easily be applied in the determination of PAHs in real chocolate samples as well as their related products.

Ionic liquid based vortex assisted liquid–liquid microextraction combined with liquid chromatography mass spectrometry for the determination of bisphenols in thermal papers with the aid of response surface methodology

A sensitive, rapid and efficient ionic liquid-based vortex assisted liquid-liquid microextraction (IL-VALLME) with Liquid Chromatography Mass spectrometry (LC-MS/MS) method is proposed for the determination of bisphenols in thermal paper. Extraction factors were systematically optimized by response surface methodology. Experimental factors showing significant effects on the analytical responses were evaluated using design of experiment. The limit of detection for Bisphenol-A (BPA) and Bisphenol-S (BPS) in thermal paper were 1.25 and 0.93μgkg-1 respectively. The dynamic linearity range for BPA was between 4 and 100μgkg-1 and the determination of coefficient (R2) was 0.996. The values of the same parameters were 3-100μgkg-1 and 0.998 for BPS. The extraction recoveries of BPA and BPS in thermal paper were 101% and 99%. Percent relative standard deviation (% RSD) for matrix effect and matrix match effects were not more than 10%, for both bisphenols. The proposed method uses a statistical approach for the analysis of bisphenols in environmental samples, and is easy, rapid, requires minimum organic solvents and efficient.

Removal of Cd(II) Ions from Simulated Wastewater by HCl Modified Cucumis sativus Peel: Equilibrium and Kinetic Study

This paper describes the adsorption of Cd(II) ions from aqueous solutions by modified Cucumis sativus peel (CSP) by HCl treatment. The optimum pH, adsorbent mass, contact time, and initial ion concentration were determined. The maximum removal efficiency was 84.85% for 20 mg/L Cd(II) ion at pH 5. The adsorption isotherms were obtained using concentrations of the metal ions ranging from 5 to 150 mg/L. The adsorption process follows Langmuir isotherm and pseudo-second-order reaction kinetics. CSPs exhibit monolayer adsorption capacity of 58.14 mg/g at 298 K. The paper also discusses the thermodynamic parameters of the adsorption (the Gibbs free energy, entropy, and enthalpy). Our results establish that the adsorption process was spontaneous and endothermic under normal conditions.

Determination of Cd, Cr, Pb and Ni contents among Parkinson's disease individuals: a case­control study

ABSTRACT Background: Various uses of metals in industries, including the domestic sphere, agriculture, medicine and technology, have led to their wide distribution in the environment. These result in raising concerns over their potential effects on human health and the environment. Because of their high degree of toxicity, Cd, Cr and Pb are some of the priority metals that are of public health significance. The levels of Cd, Cr, Pb and Ni were measured in Parkinsons disease (PD) patients. Methods: Blood samples were collected from 40 patients and 40 healthy controls, and stored at −80 °C until assayed. Atomic absorption spectrophotometry was used to determine the levels of metals. Results: The level of Pb was significantly decreased in patients than in controls. However, the difference in the level of Ni between patients and controls failed to reach significance. Cr was not detectable in patients, but it was measurable in 12 controls (controls = 0.056–2.397 µg/ml). Similarly, Cd was not detectable in patients, but it was measurable in all the controls (controls = 0.004–1.268 µg/ml). Pb was the only metal that was found in all study participants (PD = 0.012–2.758 µg/ml and controls = 0.779–9.840 µg/ml). Ni could be measured only in six patients and in all the controls (PD = 0.154–0.754 µg/ml and controls = 0.034–1.691 µg/ml). Conclusion: Patients exhibited significantly decreased levels of Pb than in controls. However, Cd, Cr and Ni were too low to be measured among the patients. This indicates that these metals might play a probable role in PD.