Ijaz Ahmad Bhatti

Gamma radiation/H2O2 treatment of a nonylphenol ethoxylates: Degradation, cytotoxicity, and mutagenicity evaluation

Gamma radiation/H2O2 treatment of nonylphenol polyethoxylates (NPEO) was performed and treatment effect was evaluated on the basis of degradation, chemical oxygen demand (COD) and total organic carbon (TOC), and toxicity reduction efficiencies. The radiolytic by-products were determined by Fourier Transform Infrared Spectroscopy (FTIR), High-Performance Liquid Chromatography (HPLC), and Gas Chromatography-Mass Spectrometry (GC-MS) techniques. Low mass carboxylic acids, aldehyde, ketone, and acetic acid were identified as the by-products of the NPEO degradation. NPEO sample irradiated to the absorbed dose of 15 kGy/4.58% H2O2 showed more than 90% degradation. Allium cepa (A. cepa), brine shrimp, heamolytic tests were used for cytotoxicity study, while mutagenicity was evaluated through Ames test (TA98 and TA100 strains) of treated and un-treated NPEO. The reductions in COD and TOC were greater than 70% and 50%, respectively. Gamma radiation/H2O2 treatment revealed a considerable reduction in cytotoxicity and mutagenicity. A. cepa, heamolytic and shrimp assays showed cytotoxicity reduction up to 68.65%, 77%, and 94%, respectively. The mutagenicity reduced up to 62%, 74%, and 79% (TA98) and 68%, 78%, and 82% (TA100), respectively of NPEO-6, NPEO-9, and NPEO-30 irradiated to the absorbed dose of 15 kGy/4.58% H2O2. NPEO-6 detoxified more efficiently versus NPEO-9 and NPEO-30 and results showed that Gamma radiation/H2O2 treatment has the potential to mineralize and detoxify NPEO.

XRD studies of chitin-based polyurethane elastomers.

Chitin-based polyurethane elastomers (PUEs) were synthesized by step growth polymerization techniques using poly(epsilon-caprolactone) (PCL) varying diisocyanate and chain extender structures. The viscosity average molecular weight (M(v)) of chitin was deduced from the intrinsic viscosity and found; M(v)=6.067 x 10(5). The conventional spectroscopic characterization of the samples with FTIR, (1)H NMR and (13)C NMR were in accordance with proposed PUEs structure. The crystalline behavior of the synthesized polymers were investigated by X-ray diffraction (XRD), differential scanning calorimetery (DSC) and loss tangent curves (tan delta peaks). The observed patterns of the crystalline peaks for the lower angle for chitin in the 2theta range were indexed as 9.39 degrees, 19.72 degrees, 20.73 degrees, 23.41 degrees and 26.39 degrees. Results showed that crystallinity of the synthesized PUEs samples was affected by varying the structure of the diisocyanate and chain extender. Crystallinity decreased from aliphatic to aromatic characters of the diisocyanates used in the final PU. The presence of chitin also favors the formation of more ordered structure, as higher peak intensities was obtained from the PU extended with chitin than 1,4-butane diol (BDO). The value of peak enthalpy (DeltaH) of chitin was found to be 47.13 J g(-1). The higher DeltaH value of 46.35 J g(-1) was found in the samples extended with chitin than BDO (39.73 J g(-1)).

Evaluation of biocompatibility and mechanical behavior of chitin-based polyurethane elastomers. Part-II: Effect of diisocyanate structure.

Chitin-based polyurethane elastomers having potential for biomedical applications with tunable mechanical properties were synthesized by step growth polymerization techniques using poly(epsilon-caprolactone) (PCL) with different diisocyanates. The prepolymer was extended using chitin and/or 1,4-butane diol (BDO). The structures of the resulted polymers were determined by Fourier transform infrared (FTIR), 1H NMR and 13C NMR spectroscopic techniques. The effect of structure of diisocyanates and chain extenders on mechanical properties and in vitro biocompatibility were investigated. The results revealed that the final polymers extended with chitin are preferred candidates for surgical threads with on going investigations into their in vitro biocompatibility and non-toxicity.

Survey of aflatoxins in chillies from Pakistan produced in rural, semi-rural and urban environments

Chilli peppers from Pakistan are consumed locally and also exported. Their quality is compromised by aflatoxins (AF) contamination. AF in chillies from rural, semi-rural and urban areas of the Punjab region of Pakistan were determined. Twenty-three (52.3%), 22 (50%) and 29 (65.9%) samples from rural, semi-rural and urban areas respectively, contained levels of aflatoxins which exceeded the European Union limits of >5 µg kg−1 for AFB1 and >10 µg kg−1 for total AF that apply to spices. Mean values for AFB1 in ground samples were 23.8, 14.8 and 14.0 µg kg−1 for rural, semi-rural and urban areas, respectively. Mean total AF in ground samples were 27.7, 17.7 and 16.2 µg kg−1 from equivalent locations. Eleven (50%), 12 (54.5%) and 14 (63.6%) whole samples from rural, semi-rural and urban areas, respectively, contained total levels of AF that exceeded European Union limits. The data indicate that individual localities have particular problems. In conclusion, the concentrations were often greater than the statutory limits set by the European Union.

Quality index of oils extracted from γ-irradiated peanuts (Arachis hypogaea L.) of the golden and bari varieties

Two varieties of peanuts were irradiated to 4, 6 and 8 kGy with Co(60). Their proximate compositions remained unaffected, but microbes were eliminated completely after irradiation to 8 kGy. HPLC was used to study tocopherols of irradiated and unirradiated oil samples. There were dose-dependent differences in physico-chemical values between the control and irradiated samples. Significant changes in tocopherol concentrations and peroxide values in the oils were observed after irradiation to 8 kGy. Fatty acid compositions did not change significantly. The study has shown that irradiation is an effective tool in preservation of peanut oil.

Modification of cellulosic fibers by UV-irradiation. Part II: After treatments effects

This work presents the comparative study on the dyeing behavior of cellulose fibers in alkaline solutions and under the influence of UV radiation. The cellulosic fabrics were pretreated followed by conventional mercerization technique or treatment with UV irradiation. For different time duration the reorganization of cellulose fibers by swelling treatments in alkaline solutions results in numerous structural modifications, causing changes of their accessibility and/or reactivity. The results revealed that the swelling of the cellulosic fibers depends on type of pre-treatment, dose of the radiation and the concentration of alkaline solution used. SEM analysis confirmed that UV irradiation of the cellulosic fibers leads to a higher swelling in comparison with any concentration of NaOH treatment. In comparison of both the treatments, the mercerized cellulosic fibers have shown better tear and tensile strength as compared to the untreated and UV irradiated one. There is adverse effect of UV radiation on the mechanical properties of UV radiation. Moreover, no loss in weight was observed after exposing the cellulose fabrics surface to UV radiation.

Modification of cellulosic fibers to enhance their dyeability using UV-irradiation

Present research was proposed to evaluate the effect of UV radiation on the dyeing of cellulosic fabrics with direct dyes. The cellulosic fabric was irradiated by using UV radiation assembly (180 W) for different time intervals i.e., 30, 45, 60, 75 and 90 min respectively. The alike set of fabrics was prepared varying the concentration of NaOH during mercerization of the fabrics. All the treated fabrics were dyed with direct dyes. The dyeing parameters such as temperature, time, pH and salt concentration were optimized. The standard methods were employed to evaluate the color strength at various levels of pH, temperature, dyeing contact time and salt concentration. Scanning electron microscope test was performed in order to evaluate the change in fibril structure and surface. The obtained results of the dyed fabrics previously treated with UV radiation and after mercerization were compared. The results revealed that the color strength of UV-irradiated fabric was high as compared to mercerized cellulosic fabrics.

Effect of UV-Radiation on Extraction and Dyeing of Cotton Fabric with Pomegranate Rind

Pomegranate (Punica granatum), which contains tannins as the main colouring component in the rind that imparts a yellowish brown colour on cotton fabric, has been selected and extracted through the use of water, methanol and ethanol. For the extraction of dye, irradiated and non-irradiated rind powders are used. The dyeing parameters, such as temperature, pH, time and material to liquid ratio (M:L) has been studied by the CIE Lab system for the optimization of dyeing conditions. Dyeing, irradiated and non-irradiated cotton fabrics have been used in order to see the effect of UV radiation on the colour strength of dye. Fastness properties, such as colour fastness to light, washing and rubbing (dry and wet), have been studied in accordance to ISO standard methods. It is found that irradiated cotton fabric not only improves the colour strength of dye, but also the colour fastness properties of irradiated cotton fabric.

Solution behaviour and sweetness response of d-Mannitol at different temperatures

The solution properties of d-Mannitol (DM) were studied to explore sweetness response and molecular interactions in aqueous solutions at different temperatures. The density (ρ) and ultrasonic velocity (μ) were measured at 20-45°C using density sound velocity metre (DSA 5000M). The results obtained were used to compute apparent and partial molar volume, apparent specific volumes, partial molar expansibility, apparent molar isentropic compressibility and compressibility hydration number. The partial molar volume (ΦV°) indicates hydrophilic interactions dominating in aqueous solution of DM. The quality of taste has been determined from apparent specific volumes (ASV) data at 20-45°C and 0.04-0.89 mol kg(-1).The apparent molar isentropic compressibility (ΦK(s)) and hydration number (nH) conferred pre-dominance of solute-solvent interactions, whereas partial molar expansibility (ΦE°) and related standards predicted structure making behaviour of DM. This study may provide new insights in elucidation of mechanistic differences between sweeteners and their mode of interactions.

MINERAL COMPOSITION OF STRAWBERRY, MULBERRY AND CHERRY FRUITS AT DIFFERENT RIPENING STAGES AS ANALYZED BY INDUCTIVELY COUPLED PLASMA-OPTICAL EMISSION SPECTROSCOPY

Mineral contents of strawberry (Fragaria x ananassa), mulberry (Morus alba, M. nigra, M. macroura, and M. laevigata) and cherry (Prunus avium) fruits at un-ripened, semi-ripened and fully-ripened stages were investigated. The concentrations (mg kg−1) of potassium (K), phosphorus (P), calcium (Ca), and magnesium (Mg) in the fruits (DW), at fully-ripened stage, varied from 2600 (mulberry) to 3300 (strawberry), 1854 (cherry) to 2954 (mulberry), 1855 (cherry) to 4375 (mulberry) and 1025 (cherry) to 2225 (mulberry), respectively. Sizeable amounts (mg kg−1) of Zn 408 (strawberry) to 1110 (mulberry) and Fe 236 (cherry) to 1080 (mulberry) were also determined. Moreover, the tested fruits contained considerable amounts of sodium (Na), manganese (Mn), aluminum (Al), and copper (Cu). Overall, the concentrations of these minerals except K were found to decrease as fruit maturity progressed. The tested fruits, especially Morus species, can be explored as a rich source of Zn and Fe, the two essential elements that are in short supply in human diet.