Kinetics of Irreversible Thermal Denaturation of Horseradish Peroxidase

Horseradish peroxidase (HRP) isolated from roots of horseradish was purified by a combination of ammonium sulfate, ion-exchange and gel filtration. The specific activity of the purified enzyme was 14.92 fold higher than the crude extract. Purified HRP was then used for kinetic and thermodynamic characterization. Irreversible thermal denaturation followed first order kinetics. The half-life (t1/2) of peroxidase was 11.55 mm at 65 °C. The enthalpy (DH*) and free energy (DG*) of thermal denaturation of HRP were 92.22 and 102.54 k JmoI,-1 respectively, at 65 °C. It was suggested that horseradish peroxidase was quite thermostable and could be used for industrial more


Chemical Study of the Raw Material in Gandghar Range, District Haripur, NWFP, for Portland Cement Manufacturing

Limestone is a valuable raw material, which is widely used in the chemical, metallurgical and construction industries throughout the world. With huge deposits of limestone in Pakistan, it is immensely used as the major raw material in the cement manuficturing. The extensive deposits of limestone are exposed in the Gandghar, Cherat and Khyber ranges around the Peshawar basin. The area of study was a part of the Gandghar range in District Haripur in Hazara where various types of raw materials (i.e., limestone, phyllite and clay) used in the cement manufacturing are present. This raw material was analyzed for the major element oxides and its chemistry was evaluated in regard to the manufacturing of Portland cement during this study. It was found that the raw mixture in the proportion of 80 % of Shekhai limestone, 2 % of Utch Khattak limestone, 3 % of greenish grey limestone, 12 % of clay and 3 % of laterite resulted in the final product of clinker having 22.57 % Si02, 4.84 % A12O3, 4 % Fe203 and 6709 % CaO. This clinker has the appropriate composition for the manufacturing of Portland cement. It is, therefore, recommended that a feasibility study should be conducted for establishing Portland cement manufacturing plant in the area for the best use of the studied raw material of the Gandghar range.  read more


Investigation of Surface Acidity of Coal by Aqueous Potentiometric Titration

Surface acidic functional groups in virgin and variously extracted coal samples were determined by aqueous patentiometric acid abase titration employing KOH as a titrant. The various extractants used in this study were H2O2, HCI, KOH and distilled water. The obtained titration curve of virgin coal showed inflections at pH 44, 64 and 8-11, which indicate that the coal surface may contain carboxylic, carbonyl, phenolic and other weak acidic groups like enols and C-H. The titration curves of treated coal samples showed a normal break at pH 4-10 range and small inflections at pH 10-11, which did not show ‘a similarity to the inflection of carboxylic acid groups but may be due to the existence of acid groups such as C02, Phenols, enols and C-H. The aforementioned extractants oxidized (by increasing the peak intensity at 1310-1250 cm’ regions due to stretching vibrations of C-O-C in ether and ester) the coal sample and were verified by FT-IR spectral more


Gold Anomaly in the Quaternary Sediments of Peshawar Basin, Shaidu Area, District Nowshera, NWFP, Pakistan

Shaidu area, a part of the district Nowshera, NWFP, lies within the Peshawar Basin. It is dominantly composed of fluvial sediments (Le., gravels, cobbles, sand and silt) deposited by the Kabul river. The area has for the first time been investigated for the occurrence of placer gold by collecting representative samples of pan concentrates. These samples were subjected to mineralogical and chemical studies. These studies suggest that visible placer gold particles are present in variable size and morphology and also have high concentration (up to 170 mg/kg) of gold in. the studied sediments. This gold is of economical grade and its high recovery (> 30 g/ ton) can be obtained by erecting the mercury amalgamation plant at the site.  read more


Comparative High Volume and Scrubbing-Based Estimation of Aerosol Lead

Aerosol lead levels were determined in the atmosphere of Rawalpindi, Pakistan, at eight sampling sites with low to high traffic density, using the standard high volume sampling and the modified dithizone scrubbing based techniques. Flame AAS method was employed to analyze aerosol particulates for Pb collected on glass fiber filters from a high volume sampler running on an 8-hourly basis. Nitric acid based digestion method was employed for the dissolution of particulate mater. In parallel, the dithizone-carbon tetrachloride scrubbing method was used to trap the particulate matter in solution at an inlet air flow rate of 1.5 LPM, at three pie-selected monitoring times: 8:00, 12:00 and 16:00 hrs. The Pb levels determined by the former technique ranged from 22 mg/m3 to 57 mg/m3 and by the latter from 18 mg/m3 to 39 mg/m1 on the same days. Meteorological parameters, such as temperature, wind speed, wind direction and relative humidity, were also recorded to evolve a probable correlation with the distribution and dispersion of Pb in the local atmosphere. The usefulness of the two techniques is herein highlighted for monitoring the metal levels in typical urban atmosphere. Data on airborne Pb distribution from other parts of the world are described and more


Recreational Water Quality in Western Malaysia: A Case Study of Kuala Woh

The pollution level of recreational water in Western Malaysia has been investigated. Kuala Woh, a famous recreational spot in Perak was taken as a case study, which covered a time period from September 2003 to April 2004. The samples were analyzed for ammonia nitrogen, chemical oxygen demand (COD), biological oxygen demand (BOD) and heavy metals. The range of quality parameters of the samples were: temperature (2049 °C - 5819 °C), pH (7.10 — 8.26), conductivity (5.4 a 267.7 mS/ cm), turbidity (0.01. 1.01 NTU), total dissolved solid (89-149 mg/ L), COD (2.1 el 1.0 mgI L), BOD (1.0- 4.3 mg/ L), ammonia nitrogen (0.03- 0.18 mg/ L) and sulphur (0.5 5e 5698 mg/ L). Although the study was limited, the results were encouraging. Most of the quality parameters with the exception of the hot patches at the recreational site followed the levels adopted by the Interim National Water Quality Standards (INWQS) for M at ays i a. On the basis of the INWQS values, the Kuala Woh recreational water can be categorized as Class 118 and considered safe for recreational purposes. The high sulfur contents and elevated temperature at the hot patches, however, may be harmful in the case of a direct body more


Dehydroacetic Acid Oxime as a New Ligand for Spectrophotometric Determination of Cobalt

Dehydroacetic acid oxime (DAO) has been used as a ligand for spectrophotometric determination of cobalt. The reaction took place in a slightly acidic medium at pH 5.8 and Coe DAO complex showed lmax at 645 nm and the absorption was observed to be free from any spectral interferences.  read more


Electron Ionization Mass Spectrometric Studies of 3-(4’-Chlorophenylethyl) isocoumarin and Its 3, 4-Dihydroisocoumarin

Electron ionization mass spectra of 3(4’ach1orophenyIethyl)isocoumarin (I), dihydroisocoumarin (2) and kern-acid (3) are discussed. The mass spectral fragmentation patterns are assigned with the help of LREIMS.  read more


Two-Step Synthesis and Characterization of Carboxymethylcellulose from Rayon Grade Wood Pulp and Cotton Linter

Carboxymethylcellulose (CMC) was prepared from bleached cellulose puips obtained from the wood of Eucalyptus globulus (Eup), Picea smithiana (Picp) and cotton linter pulp (CU’), which are used for viscose rayon fiber. The chemical composition of cellulose pulps (alpha-cellulose, hemi-cellulose, moisture, ash, intrinsic viscosity and color brightness) was also determined. The dried cellulose was alkalized using 40 % NaOH at 25 ‘C for 1 s5 hour. Sodium monochloroacetic acid (MCA) from 5-7 g per 5 g cellulose was added to the slurry and the temperature was adjusted to 55 ‘C for 3.5 h. The puips carboxymethylated by one successive reaction step, were again etherified, using monochioroacetic acid as an etherifying agent and isopropyl alcohol as a solvent. The best result of etherification was obtained in the case of cotton linter pulp. The degree of substitution (DS) of CMC was found to be dependent unto the source of cellulose, but generally it was high in the case of cotton linter pulp. The second etherification reaction step increased the DS up to 1.9, by increasing the concentration of MCA, which in turn improved the CMC solubility in water. Qualitative and quantitave analysis of CMC were carried out to determine the moisture, ash, sodium chloride, degree of substitution, purity and viscosity of carboxymethylcellulose. This investigation helped to find the proper conditions for the etherification of rayon grade pulps and showed that high quality CMC can be prepared from cotton linter pulp by two consecutive etherification more


Synthesis, Characterization and Biological Studies of 2-PhenylmethyIaminoI benzoic acid and Its Complexes with Co (II), Ni (II), Cu (II) and Zn (II)

2-(Phenylmethylaminol benzoic acid and its complexes, with Co (II), Ni (II), Cu (II) and Zn (II), have been synthesized and were characterized on the basis of physical, analytical, conductance and spectroscopic data. The ligand and its complexes were been screened for antibacterial activity against different bacterial strains such as Escherichia coil, Staphylococcus auras and Pseudomonas aeruginosa. These studies demonstrate that the complexes are more antibacterial as compared to the uncomplexed ligand.  read more