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Quality Control of Some Water, Food, and Drug Samples in Erbil City, Iraq Prof. Dr. Nabil A. Fakhre Dept. of Chemistry, College of Education/ Scientific Depts. , Univ. of Salahalddin, Erbil, IRAQ [email protected] com
Qualitycontrol (QC) is a procedure or set of procedures intended to ensure that a manufactured product or performed service adheres to a defined set of quality criteria or meets the requirements of the client or customer. This global quality management system provides the basis for analyzing customer requirements, defining theprocesses that contribute to the achievement of a productor service that is acceptable to the customer, and provisions for keeping these processes in control. QC activities include general methods such as accuracy checks on data acquisition and calculations and the use of approved standardized procedures for emission calculations, measurements, estimating uncertainties, archiving information and reporting. Higher tier QC activities include technical reviews of source categories, activity and emission factor data, and methods.
SEMI-AUTOMATED DETERMINATION OF NITARATE IN TAP WATER SAMPLES USING DIZOTIZATION- COUPLING REACTION Nabil A. Fakhre, and Hemen A. Kadir Nitrate is an important intermediate in the biogeochemical cycling of nitrogen in natural water. Because of the relative stability of the nitrate ion, most nitrogenous materials in environmental media tend to be converted to nitrate. Therefore, all sources of nitrogen (including organic nitrogen, ammonia and fertilizers) should be considered as potential sources of nitrate. Nitrate is relatively non-toxic, and it can be converted readily by bacteria to nitrite, which is also one of the pollutants in the atmosphere and natural water. Nitrate, converted to nitrite, may reacted with amines (proteins found in some foods, medications, and water) to produce nitrosamines, which have been found to be carcinogenic in animals. Some of types of cancer linked to this reaction. The maximum contaminated level for nitrate in drinking water is 45 ppm, and the value of total nitrogen at the outlet of wastewater plant or in rivers and lakes should be below 18 ppm, which equivalent to about 59 ppm of nitrite and 79. 7 ppm nitrate. Semi- automated method has been investigated for the determination of nitrate depending upon the reduction of nitrate to nitrite using a mini-column of amalgamated cadmium redactor. The produced nitrite was reacted with N, N-dimethyl-p-phenylenediamine dihydrochloride (NDMPDAH), to produce a water soluble, colorless diazonium ion, which subsequently coupled with resorcinol to form an azo dye in the alkali medium to be detected in a spectrophotometer with a flow cell of 30 ul. Nitrate was determined in the concentration range (0. 3 - 6. 0) ppm with detection limit 0. 15 ppm and sampling rate of 60 samples/h. The method is with acceptable precision and accuracy depending upon the values of relative standard deviation and relative error percentage. The effect of 35 cations and anions on the determination of nitrate was studied. To eliminate the influence of some cations two methods have been used; column of cationic exchanger and EDTA solution. The method was applied successfully for determination of nitrate in various wastewater samples in different locations in Erbil City after the removal of turbidity, oil and grease. The results were compared to those obtained with standard NEDA method.
Extraction-Spectrophotometric Determination of Nitrate in Polluted Water and Soil Samples using Diazo-Coupling Reaction Chinar M. Rasheed and Nabil A. Fakhre* Department of Chemistry, College of Education, University of Salahalddin, Erbil, Iraq Abstract A simple and sensitive spectrophotometric method was described for the determination of nitrate. The method is based on the reaction of nitrite with 3 -amino-5 -methyl isoxazole to form a diazonium ion, which is coupled with resorcinol in an alkaline medium to form the azo dye, with a maximum absorption at 354 nm. Nitrate is determined by it’s reduction to nitrite using amalgamated cadmium column. Beer’s law is obeyed over the range of 0. 04 -6 g/ml, with a detection limit of 0. 02 g/ml. The molar absorptivity, Sandell index are 2. 482 x 10 4 L/mol. Cm and 0. 00249 g/ml respectively. The effect of 35 cations and anions were studied. The method was applied for determination of nitrate in polluted water and soil samples, the results were compaired with the standard method, NEDA. The prepared azo dye was extracted into 1: 1 (v/v) mixture of isoamyl alcohol-isobutyl methyl ketone. Nitrate was determined over the range of 0. 005 -2 g/ml with a detection limit of 0. 003 g/ml and molar absorptivity 6. 486 x 104 L/mol. cm.
Spectrophotometric Determination of Nitrite in Curing Meat Samples Nabil A. Fakhre and Hemn A. Qader Nitrite ion is an important intermediate in biological nitrogen cycle and is present in soils and surface waters. Nitrite is also a versatile chemical agent, which has found numerous applications ranging from dye manufacture to food preservation. Alkali nitrites and nitrates, along with sodium chloride have long been used in the curing of meat products to prevent bacterial spoilage and to enhance the flavor, color and texture of these food products. Nitrite oxidizes hemoglobin to methemoglobin, which is unable to transport oxygen, and nitrites react with amines and amides to form nitrosamines, which are potent carcinogens. Current legislation (EU Directive 95/2) suggests maximum amounts to be added at the beginning of processing in various meat products and imposes a maximum residue of 50 μg/ml nitrites and 250 μg/ml nitrates in cured meat products that have not been thermally treated. The nitrite content in meat products has been regulated and the majority of the analytical methods recommended by the legislations of different countries to determine its content are based on the Saltzman modification of the classical Griees method. Many methods have been reported for the spectrophotometric determination of nitrite. In the present work, a simple procedure for the spectrophotometric determination of nitrite is described. The method is based on the reaction of acidified 2 -aminobenzoimidazole as the diazotizing agent with nitrite to produce water solublediazoniumion, which subsequently coupled with orcinol to give azo dye having maximum absorption at 305 nm. The method has been successfully applied to the determination of nitrite in curing meat samples.
DETERMINATION of ACRYLAMIDE in POTATO CHIPS SAMPLES USING DIFFERENT ANALYTICAL TECHNIQUES Nabil A. Fakhre and Bnar M. Ibrahim Chemistry Department, College of Education /Scientific Departments, University of Salahaddin, Erbil / Kurdistan Region, Iraq [email protected] com Acrylamide is formed in some foods cooked at high temperature (120 -170ºC) by the reaction of the amino acid asparagines with a reducing sugar such as glucose. Acrylamide is genotoxic and carcinogenic in studies in animals. It causes increased tumour incidence at a variety of sites. The international agency on research on cancer has classified acrylamide as probably carcinogenic to humans. Two sensitive and fast batch and flow-injection spectrophotometric methods for the determination of acrylamide are proposed. The methods were based on oxidation-reduction reaction of acrylamide with potassium permanganate. The calibration graphs are linear over the ranges 1. 0– 8. 0 and 2. 0 -13µg/ml of acrylamide, with detection limits of 0. 6 and 1. 0µg/ml, respectively. The methods are applied to the routine analysis of acrylamide in potato chips samples. It confirms that the analytical procedure employed for the analysis is suitable and reliable for its intended use. Acrylamide was also determined in the presence of glucose and asparagines. Reduction of some cationic interference was carried out in the batch and flow injection analysis using cationic exchanger of hydrogen form with 2. 5 –mm internal diameter, 15 -cm length of packing and flow rate 0. 5 ml/min. The proposed first and second derivative methods for determination of acrylamide, are simple, rapid (as it only requires measurements of n. D values at a single wavelength). They were used for identification of the acrylamide depending upon characteristic peaks at certain wavelengths or ranges. The first and second derivative spectra of the mentioned compound have been used for determination of the compounds at different ranges of concentration depending upon the measurements of the heights of the peak to the baseline at certain wavelengths. HPLC was used as a standard method for qualification and quatitation of acryl amide in different potato chips samples, and the results obtained were agreed with those of the proposed methods.
On–line separation and preconcentration for histamine determination in fish meal using cation– exchanger resin Nabil A. Fakhre and Mohammad S. Abdulla Biogenic amines are a group of biologically active organic compounds normally produced by decarboxylation of free amino acids. Biogenic amines are present in a variety of foods and have been widely documented as occurring in fish and fish products, meat, wine, cheese and fermented foods. The presence of biogenic amines in these foods is an indication of food spoilage which is dependent upon the availability of free amino. Histamine, which is the most important biogenic amine, can cause poisoning as a result of the ingestion of food containing high levels of this amine. To a series of 25 ml volumetric flasks, 4. 0 ml of 0. 2% p-toluidine (prepared in 0. 5 M HCl), 0. 5 ml of 0. 5% sodium nitrite, 12. 5 to 175 μg of histamine and 2. 0 ml of 1 M KOH were added. The solution completed to mark with ethanol after two minutes. Absorbance measurements were carried out against reagent blank. Fig. 2 -2 shows FI manifold used for histamine determination. A multi channel peristaltic pump was used for propelling p-toluidine (0. 5% in 1 M hydrochloric acid) solution, 0. 5% sodium nitrite solution and 1 M potassium hydroxide solution, with flow rates 0. 9, 0. 8 and 0. 4 ml/min for solutions respectively. A 175 μl of histamine sample was injected through the injection valve. Three reaction coils were used in the system with lengths 5 cm (RC 1), 40 cm (RC 2) and 40 cm (RC 3). The merged streams were passed through a quartz flow cell (30 μl, 10 mm path length) in a spectrophotometer.
Fl. OW-INJECTION SPECTROPHOTOMETRIC DETERMINATION OF CHLOROGENIC ACID IN SOME NATURAL SAMPLES Nabil, Adil Fakhre and Rizgar Mohamad Hassan Polyphenols, are a group of chemical substances present in plants which play an important role during enzymatic browning. They are responsible for the color of many plants, such as apples; part of the taste and flavor of beverages (apple juice, tea). Chlorogenic acid (CGA) is a major phenolic natural product isolated from the leaves and fruits of dicotyledonous plants, including the coffee beans which typically contain 5 -8% of CGA. Biologically, it is an important polyphenol; it is found widely in plants, black teas, soya beans, wheat, apple juice, tobacco, some traditional Chinese medicines, beers, wines, Chinese herbs 2 and accounting for > 75% of the total phenolic acids content extracted from the eggplant sample, also the presence of CGA in sunflower seeds is well-known. CGA not only has the function of antioxidation, inhibiting hypertension and stimulating the flowering of plants, but also affects the activity of trypsin, amylase and other enzymes. CGA is the main component producing the bitter taste in crude coffee and thus deliberative elimination of CGA into the instant coffee has been adopted extensively to improve the taste of various kinds of coffees. The contents of CGA in different areas and in various foods are also quite different. Therefore, it is very important to establish some quantitative methods to monitor the concentration of CGA in all kinds of real samples. A flow-injection spectrophotometric system was applied for determination of chlorogenic acid using 3 -amino-5 methylisoxazole as diazotizing agent in the linear range of 1. 0 -50. 0 g/ml, with the sample volume of 175 µl and the detection limit of 0. 30 g/ml. The rate of sampling was 60 samples/h, with the RSD% and Error% of 2. 254% and + 3. 4966%, respectively. The influences of seventeen phenolic compounds (as interferences) such as dopamine, tyrosine, catechol, tannin, 2, 4 -dihydroxybenzoic acid, caffeic acid and p-cresol on determination of chlorogenic acid were studied. An ultrasonic technique was used for extracting chlorogenic acid in the samples by using 80% (v/v) methanol aqueous solution. The proposed method was successfully applied for the determination of chlorogenic acid content in various natural samples such as grape, tobacco and black tea.
Studies on Physico - Chemical Characteristics of Some Edible Oils and Authentication of Triacylglycerols using HPLC Nabil A. Fakhre and Hemen K. Kadir The aim of the study S S It is intended to study the properties of some of edible oil samples through the phsico - chemical tests like (refractive index, specific gravity, viscosity, iodine value, peroxide value, percentage of free fatty acid and p. H value). The study aims to shed more light on the oil acidity and composition of saturated and unsaturated fatty acids. The adulteration was the second aim of the present study using (RP-HPLC/RI detector) to confirm authenticity of triacylglycerols and to identify the composition of blends of some edible vegetable oils.
FLOW-INJECTION AND STOPPED FLOW SPECTROPHOTOMETRIC DETERMINATION OF DOPAMINE HYDROCHLORIDE IN PHARMACEUTICAL PREPARATIONS Nabil A. Fakhre, and Mohamad S. Abdullah Dept. of Chemistry, College of Science Education, Univ. of Salahaddin, Erbil, IRAQ. [email protected] com y words: Flow-injection, Stopped flow, Spectrophotometric determination, Dopamine. The catecholamines participate in the regulation of a wide variety of physiological function in humans. In principle they control cardiac output and apportion blood flow. Dopamine is one of most significant catecholamines. It is naturally occurring amine used for treatment of acute congestive failure and renal failure. Dopamine hydrochloride is determined by flow injection and stopped-flow. The assay depends on the nitrosation of the aromatic ring followed by forming a stable colored compound in alkali medium. The reaction has a maximum absorption at 377 nm. The method obeyed Beer´ s law in the range 40 -160µg/ml. The number of sample throughput is 35 s/hour with injected sample 200µl. To increase the sensitivity of the method stopping flow of the reaction zone in the flow cell at a regulated time after the injection of sample was made. The optimum time of stopping was 60 sec. The method obeyed Beer´ s law in the range 15 -120 µg/ml. Both methods were applied for determination of dopamine hydrochloride in pharmaceutical preparation with recoveries 95. 0 -97. 0%.
Flow injection Spectrophotometric Determination of Folic Acid in Some Pharmaceutical Preparations using Diazotizing-Coupling Method Nabil Adil Fakhre and Mohammad Salim Abdullah Folic acid (FA) is extremely important vitamin that occurs naturally in foods. It is essential for human. Folacin is a generic name covering FA and related compounds having the same biochemical activities of FA. Folic acid and folate (the anion form) are forms of water soluble B-vitamins ( Champe and Harvey, 1994). It plays a key role in one-carbon metabolism, and is essential for the biosynthesis of the purines and pyrimidines. Folic acid deficiency is probably the most common vitamin in USA, particularly among pregnant women and alcoholism ( Marks et. al, 1996). Folic acid helps form building blocks of DNA, the body genetic information, and building cks of RNA, needed for protein synthesis in all cells. The present study describes a simple, rapid and sensitive method for the determination of folic acid at 435 nm. Folic acid was diazotizated with nitrous acid then coupled with sulphanilic acid. Nitrous acid (0. 5% Na. NO 2 in 0. 5 M HCl), 0. 1% sulphanilic acid and 0. 25 M sodium hydroxide solutions were propelled at flow rates 0. 6 ml/min. Folic acid solution (10μg/ml) was injected with sample volume 125μl to react with the nitrous acid solution in a reaction coil of 10 -cm. The proposed flow system method was linear in the range 6. 0 to 25. 0 µg/ml. The precision and accuracy of the methods were checked. The effects of foreign species were tested. The proposed method was successfully applied to the determination of folic acid in commercial folic acid tablets. The results are compared with that of standard method (HPLC).
Determination of Gasoline and Kerosene in a Mixture Using Peak-to -Peak Derivative Spectroscopic Method Nabil A. Fakhre Although UV-visible spectra do not enable absolute identification of an unknown n substance, they frequently are used to confirm identity through comparison of the measured spectrum with a reference spectrum. Typical multispectral analysis methods treat each spectral band as an independent variable, a reasonable assumption for multispectral data but not really appropriate for hyperspectral data. In spectroscopy, particularly in infra-red, UV and visible absorption, fluorescence, and reflectance spectrophotometry, differentiation of spectra is a widely used technique, referred to as derivative spectroscopy. Derivative spectroscopy has the potential of greatly increasing the application of UV-visible spectroscopy. Derivative methods have been used in analytical spectroscopy for three main purposes, spectral discrimination, spectral resolution enhancements, and quantitative analysis. Therefore, a simple and rapid method is described for the simultaneous quantitative analysis of gasoline and kerosene in a mixture using first, second, third and fourth derivative spectroscopy. Peak-to-peak heights were used to find various concentration ranges of gasoline and kerosene. First derivative spectra were used for determination of 10 -60% and 40 -80% Gasoline and 40 -90% and 20 -60% kerosene. Whereas second and third derivative spectra have been used for determination of 40 -80% gasoline and 20 -60% kerosene. Fourth derivative spectra were used for determination of 20 -80% gasoline and kerosene.
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