Abid Ali Khaskheli

Rapid detection of melamine adulteration in dairy milk by SB-ATR-Fourier transform infrared spectroscopy

Melamine is a nitrogenous chemical substance used principally as a starting material for the manufacture of synthetic resins. Due to its very high proportion of nitrogen melamine has been added illegitimately to foods and feeds to increase the measured protein content, which determines the value of the product. These issues prompted private as well as governmental laboratories to develop methods for the analysis of melamine in a wide variety of food products and ingredients. Owing to this fact present study is aimed to use single bounce attenuated total reflectance (SB-ATR) Fourier transform infrared spectroscopy (FTIR) method as an effective rapid tool for the detection and quantification of melamine in milk (liquid and powder). Partial least-squares (PLS) models were established for correlating spectral data to melamine concentration with R(2)>0.99, and RMSEC 0.370. Linear calibration curves were obtained over the calibration range of 25-0.0625%. The LOD and LOQ of the method was 0.00025% (2.5 ppm) and 0.0015% (15 ppm) respectively. Proposed SB-ATR-FTIR method requires little or no sample preparation with an assay time of 1-2 min.

Quick determination of melamine in infant powder and liquid milk by Fourier transform infrared spectroscopy

A simple, cost-effective and environmentally friendly analytical method was developed for the quantification of melamine (MEL) in liquid milk and infant powder by using transmission Fourier transform infrared (FT-IR) spectroscopy. Standards and samples were analyzed in the form of a KBr pellet for recording FT-IR spectra. Partial least squares calibration was established in the FT-IR region, 851.62–798.39 cm−1, with a linear range of 0.001–1%. An excellent coefficient of determination (R2) of 0.9999 was achieved, with minimum errors in the root mean square error of calibration and the root mean square error of prediction, for which the values were 0.17 and 3.49, respectively. The accuracy of the calibration model was also verified using the root mean square error of cross-validation, which was found to be 2.25. The limit of detection and the limit of quantification of the method were 0.0001% (1 ppm) and 0.00035% (3.5 ppm), respectively. The method was successfully applied to liquid and infant powder milk samples and gave good recoveries (98.9–100.2%). The FT-IR method developed here is efficient, accurate and appropriate for MEL detection in the dairy industry, with a reduced cost and a short analysis time.

Synthesis of Highly Stable Cobalt Nanomaterial Using Gallic Acid and Its Application in Catalysis

We report the room temperature (25–30°C) green synthesis of cobalt nanomaterial (CoNM) in an aqueous medium using gallic acid as a reducing and stabilizing agent. pH 9.5 was found to favour the formation of well dispersed flower shaped CoNM. The optimization of various parameters in preparation of nanoscale was studied. The AFM, SEM, EDX, and XRD characterization studies provide detailed information about synthesized CoNM which were of 4–9 nm in dimensions. The highly stable CoNM were used to study their catalytic activity for removal of azo dyes by selecting methyl orange as a model compound. The results revealed that 0.4 mg of CoNM has shown 100% removal of dye from 50 μM aqueous solution of methyl orange. The synthesized CoNM can be easily recovered and recycled several times without decrease in their efficiency.

Efficient entrapping of toxic Pb(II) ions from aqueous system on a fixed-bed column of fungal biosorbent

Abstract The present research dealt with the successful viability and practicality of Pleurotus eryngii packed bed column for Pb(II) ions biosorption. To achieve the aim of the project, the impact of different parameters including flow rate, initial concentration of Pb(II) ions and bed height were optimized. The column models, i.e.,Thomas and Bed Depth Service Time (BDST) were investigated to assess the column efficiency towards entrapping targeted ion. The adsorption capacity, rate constant and correlation coefficient related to each model for column sorption were also calculated. The adsorption capacity enhanced by increasing the bed height and decreasing initial Pb(II) metal ion concentration along with the flow rate. The maximum Thomas model adsorption (entrapping) capacity was obtained 3.30 mg g−1 for initial concentration of 20 mg L−1 at a constant flow rate of 1 ml min−1, bed height of 3 cm and pH 7. The experimental results implied and affirmed the suitability of the P. eryngii fungal biosorbent for Pb(II) ion biosorption with its nature being favourable, efficient and environment friendly.

One-pot conjugated linoleic acid production from castor oil by Rhizopus oryzae lipase and resting cells of Lactobacillus plantarum

Conjugated linoleic acid (CLA) has attracted as novel type of fatty acids having unusual health-promoting properties such as anticarcinogenic and antiobesitic effects. The present work employed castor oil as substrate for one-pot production of CLA using washed cells of Lactobacillus plantarum (L. plantarum) and lipases as catalysts. Among the screened lipases, the lipase Rhizopus oryzae (ROL) greatly assisted resting cells to produce CLA. Mass spectral analysis of the product showed that two major isomers of CLA were produced in the reaction mixture i.e. cis-9, trans-11 56.55% and trans-10, cis-12 43.45%. Optimum factors for CLA synthesis were found as substrate concentration (8 mg/mL), pH (6.5), washed cell concentration (12% w/v), and incubation time of 20 h. Hence, the combination of ROL with L. plantarum offers one pot production of CLA selectively using castor oil as a cost-effective substrate.