Estimation of Selenium(IV) in Human Hair, Nails, Blood samples and Wheat and Jaggery Samples using Morpholine Dithiocarbamate

Transcription

1 Research Article Estimation of Selenium(IV) in Human Hair, Nails, Blood samples and Wheat and Jaggery Samples using Morpholine Dithiocarbamate K. Madhavi 1* and K.Saraswathi 2 1 Department of Chemistry, VNR Vignana Jyothi College of Engineering & Technolog y, Hyderabad, Telangana State, India 2 Professor in Chemistry (Retd.), S.V.University, Tirupati, Andhra Pradesh, India Abstract A rapid, highly sensitive and selective spectrophotometric determination of selenium (IV) is studied. The maximum absorption of the selenium morpholine dithiocarbamate complex in chloroform is at 350 nm in sodium acetate-acetic acid buffer medium of ph 4.0. The formed complex has a stability of 12 hours. Interference due to various cations and anions has been investigated. The optimum reaction conditions and other analytical parameters are reported. The proposed method has been applied to detect the levels of selenium in human hair, nails, blood samples and jaggery and wheat samples. Keywords: Spectrophotometry, Morpholine dithiocarbamate (MDTC), Selenium (IV), Human hair, nails, blood samples and wheat and jaggery samples *Correspondence K. Madhavi, madhavik@vnrvjiet.in Introduction Selenium is essential for a number of important enzymes in animals as well as in humans. It has been proved as a protective agent against cancer in man. The presence of selenium in human erythrocyte, glutathione peroxidase protects accumulation of hydrogen peroxide and organic peroxides in cells and tissues which are involved in the initiation and promotion of cancer in human beings [1-4]. Selenium also protects animals against mercury toxicity. Increased dietary selenium intakes reduce the effects of mercury toxicity [5]. Acute and chronic selenium poisoning results in alkali diseases and blind staggers. The prolonged use of selenium sulphide causes skin lesions, tremors and loss of appetite [6]. Selenium is an essential element for anti oxidation reactions in humans and animals [7]. Selenium has been recognised as a dietary essential for the normal functioning of many of the systems of the body [8]. Dietary selenium comes from nuts, cereals, meat, mushrooms, fish, and eggs. Brazil nuts are the richest ordinary dietary source (though this is soil-dependent, since the Brazil nut does not require high levels of the element for its own needs). In descending order of concentration, high levels are also found in kidney, tuna, crab, and lobster [9]. In view of the importance of selenium in diverse fields particularly its role in cancer the metal ion is selected for its spectrophotometric determination using (MDTC) as a reagent. Experimental Reagents A stock solution of selenium (IV) was prepared by dissolving gms of sodium selenite in distilled water. Sodium morpholine dithiocarbamate solution was prepared in double distilled water. All other chemicals were of A.R grade. Chem Sci Rev Lett 2014, 3(12), Article CS

2 Instrumentation Systronic, PC-Based Double Beam spectrophotometer-2202 was used for absorbance measurements. A digital ph meter (model no L1120), of Elico make is employed for ph measurements. Atomic absorption spectrophotometer, Perkin Elmer model 2380 with a sensitivity of mg/lit and slit width 0.7 nm was used for the analysis of samples. Method To a solution containing 4.0 ppm ml -1 of selenium, 2.0 ml of 0.2 M sodium acetate acetic acid buffer of ph ~4.0, 1.6 ml of 1.26 x 10-2 M (MDTC), 1.0 ml of 0.2 M MgSO 4 as salting out agent are taken into a 60.0 ml separating funnel and the contents are extracted with 5.0 ml of chloroform. The organic layer containing complex is separated and the spectrum is recorded. The reagent spectrum is used as a blank. The spectrum of Se(MDTC) 4 complex has a maximum absorption at 350 nm where neither the reagent nor the metal ion has any absorption. This is selected for quantitative measurements. Results and Discussion Extraction as a function of ph In order to obtain the optimum extraction condition for Selenium, the extraction was carried out at various ph ( ).It is seen that the absorbance values of the metal complex increased with increase in ph from and remained constant from 4.0 and 6.0. However, the values fall down from ph 7.0 onwards. The extraction was found to be quantitative in the ph range and hence, ph 4.0 was selected for further studies. (Figure 1) Effect of salting out agents Figure 1 Effect of ph on Se(IV)-MDTC Magnesium sulphate as salting out agent is found to enhance the extractability of the complex into chloroform. From the observations it is found that 1.0 ml of 0.2M MgSO 4 is sufficient for extracting the complex into chloroform in a single step. Chem Sci Rev Lett 2014, 3(12), Article CS

3 Effect of reagent The effect of variation in concentration of MDTC shows that 1.6 ml of (MDTC) is found to be sufficient for quantitative precipitation of the metal ion. Effect of solvent Figure 2 Effect of reagent concentration-se(mdtc) 4 The suitability of various solvents was investigated using organic solvents such as n-butanol, chloroform, carbon tetrachloride, ethyl acetate, benzene, xylene, toluene, iso-amyl alcohol, ether, etc. The extraction of selenium with MDTC was found to be quantitative, when chloroform used as a solvent. Therefore, chloroform was used as a solvent for the entire study. Beer's law and sensitivity Calibration graph for selenium was constructed under optimum conditions. The graph obeys Beer's law in the range of 0.4 to 4.0 ppm for selenium. The molar absorptivity and Sandell's sensitivity of the system were found to be x 10 5 Lit mol -1 cm -1 and ppm/cm 2 respectively. (Figure 3) Figure 3 Calibration plot of Se(MDTC) 4 Chem Sci Rev Lett 2014, 3(12), Article CS

4 Applications Estimation of selenium in human Hair, Nails and Blood samples & Jaggery and Wheat powder Biological Samples: (Human Hair, Nails and Blood samples) 10g or ml of the sample is digested with a mixture of sulphuric acid and perchloric acid in 3:4 ratio under reflux at 75 0 C for 2 hours. The temperature is then raised to C and kept for 10 minutes, and is cooled to room temperature. The content is dissolved in hydrochloric acid and heated to C for 10 minutes and is cooled, diluted to 5.0 ml with double distilled water [10, 11]. Agricultural Samples: (Wheat powder and Jaggery) (Dry ash method): 20g of the powdered sample is taken in a silica crucible, heated to oxidise organic matter and ashed at C in a muffle furnace for 3-4 hours. The ash is dissolved by heating with 5.0 ml of 2N HCl, filtered through an acid washed filter paper into a volumetric flask and the residue is washed with hot water. The washings are also collected in to the volumetric flask and finally made up to 10.0 ml with distilled water [12]. Table 1A Estimation of Selenium in Human Hair S.No. Selenium, ppm Selenium found* in the samples, ppm/g Added Recovered MDTC AAS ml of sample solution is used. Table 1B Estimation of Selenium in Human Nails S.No. Selenium,ppm Selenium found* in the samples;ppm/g Added Recovered MDTC method AAS method ml of the samples solution is used. Chem Sci Rev Lett 2014, 3(12), Article CS

5 Table 1C Estimation of Selenium in Human Blood S.No. Selenium,ppm Selenium found* in the samples;ppm/g Added Recovered MDTC method AAS method ml of the sample solution is used. *Average of two individual determinations Table 2 Estimation of Selenium in Jaggery and Wheat powder samples Sample Selenium,ppm Selenium found* in the samples;ppm/g Added Recovered MDTC method AAS method Jaggery Wheat Powder ml of the sample solution is used. Conclusions The absorbance values are referred to the calibration plot already drawn with the standard Se (IV) solution and the amount of selenium present in the various samples is calculated. The values are compared with the values obtained by AAS method and are in good agreement. Acknowledgements I wish to gratefully acknowledge to the VNR Vignana Jyothi Institute of Engineering & Technology for providing necessary facilities for experimental work. References [1] Ananda Prasad, S., Trace Elements in Human Health and Disease Vol II, Academic Press, New. York [2] Awasthi, Y.C., Dad D.D., Lal, A.k., and Srivastava, S.K., Biochem. J.,1979,177, 471. [3] Burton, G.W., Cheeseman, K.H., Ingold, K.V., and Slater, T.F. Biochemical Society Transactions., 1983, 2, 261. Chem Sci Rev Lett 2014, 3(12), Article CS

6 [4] Gromadzinska, J., Wasowicz, W., Sklodowska, M., Pered, D. and Popodiuk, S., Annals of Clinical Research., 1988, 20, 177. [5] Mazokopakis, EE; Papadakis, J A; Papadomanolaki MG; Batistakis, AG; Giannakopoulos, TG; Protopapadakis E; and Ganotokis, ES; Official Journal of the American Thyroid Association., 2007, 17(7), [6] Conor Reilly., Metal Contamination of Food, Applied Science Publishers Ltd., London, [7] Helina Hartikainen and Tailin Xue, Vieno Piironen Plant and Soil., 2000, Vol. 225, pp [8] Roderick C. McKenzie, John R. Arthur, and Geoffrey J. Beckett. Antioxidants & Redox Signaling., 2004, Vol (2), [9] Barclay, Margaret N. I.; MacPherson, Allan. and Dixon James "Selenium content of a range of UK food". Journal of food composition and analysis., 1995, 8 (4), [10] Liu, X., Tu. Y., Cheng. W., and Wu. Z., Shengwu Huaxe Yu Shenguru Wuli Jinzhan. 1987, 6, 52. [11] Zang, S and Yang, Q., Anal. Lett., 1988, 159. [12] Gorsuch, T.T., Analyst., 1959, 84, , by the Authors. The articles published from this journal are distributed to the public under Creative Commons Attribution License ( Therefore, upon proper citation of the original work, all the articles can be used without any restriction or can be distributed in any medium in any form. Publication History Received 09 th Nov 2014 Revised 25 th Nov 2014 Accepted 16 th Dec 2014 Online 30 th Dec 2014 Chem Sci Rev Lett 2014, 3(12), Article CS