DETERMINATION THE CONCENTRATION OF SOME METALS IN IMPORTED CANNED FOOD AND CHICKEN STOCK

This study was carried out to determine the level o f same selected metals namely Cd, Cr, Cu, Fe, K, Mg , Mn, Ni, Pb, Zn, As, Se, Al and V in some imported c anned foods and chicken stock purchased from the local market in Riyadh, Saudi Arabia. The measureme nts were performed using inductively coupled plasma-optical emission Spectrometer (SPECTRO) anal ytic instruments. The result showed that the average concentration of the elements was 0.0007 fo r Cu, 0.0197 for Fe, 0.0029 for Mn, 0.0018 for Ni, 0.0120 for Zn and 0.0005 for Cr, 0.001 for Cd, 0.01 37 for Al, 0.0079 for AS and 0.0167 for Se. In comparison the concentration of heavy metals and es sential metals in the current investigation with World Health Organization and Food and Agriculture Organization WHO/FAO legal limits.The average concentration of all heavy metals and essential ele m nts were much lower than the reference limits. Based on the obtained results it can be con cluded that the imported canned foods and chicken stock are free of heavy metals contamin tio . Keyword: Chicken Stock, Canned Food, Essential Metals, Heav y Metals and ICP-OPS


INTRODUCTION
Some metals play an important role in the effective operation of biological systems and essential to human health (Se, Mn, Cu, Ca, Fe, Zn, Cr), though they're probably harmful if consumed in considerable quantities (Mohammed et al., 2011). Heavy Metals create a major contribution to environmental contamination due to human activities like mining, smelting, power transmission, intensive agriculture or heavy metal contamination affects the biosphere in several places worldwide (Aliu et al., 2013). There are some heavy metals could also be harmful to health like As, Pb, Cd and Hg haven't any identified helpful biological operation and long exposure could also be unhealthful even at low doses. Heavy metals are possible environmental pollutants with the ability of having human health problems if present in excess in the food we consume. They are given special interest in all over the world because of their poisonous effects even at even in low concentrations (Das, 1990). Though some individuals exposed to venomous elements, particularly in the workplace, for most people the main source of exposure to venomous elements is through the food (Leblanc et al., 2000). Food consumption had been specified as major route for human vulnerability to venomous metals, compared with different ways in which of exposure like inhalation and skin contact. US Environmental Protection Agency (US EPA), Joint FAO/WHO Expert Committee on Food Additives (JECFA) and Institute of Medicine of the National Academies (IOM) have given tips on the intake of trace by human beings. The IOM of the National Academies suggested the recommended the suitable quantity and also the the maximum allowable limit for some major elements (IOM, 2002;2003). It is necessary to measure the levels of heavy metals in food and to report on possible contamination that would pose a threat to human health.. Several cases of human illness, disorders, breakdowns and deformation of organs as a result of metal toxicity have been reported (Järup, 2003). The level of heavy metals in foodstuffs have been Science Publications AJES reported around the world by (Wu Leung and Butrum, 1972;Jorherm and Sundstroem, 1993;Pennington et al., 2005;Hussein and Bruggeman, 1997). This study discusses the evaluation of heavy in some imported canned foods and chicken stock in light of international standards allowable limit set by WHO and FAO.

Study Area
Riyadh is the capital city of the Kingdom of Saudi Arabia with an area of about 1554 km². It is located centrally in the Najd region with a population that is expected to reach over 5.2 million in 2007, (Fig. 1). Riyadh is the major part of Riyadh Province. It is situated in the centre of the Arabian Peninsula on latitude 34°-38° north and longitude 46°-43° east 600 m above sea level.

Samples Collection and Preparation
A total of 21 different type of imported canned foods (tuna, sardine and chicken stock) samples were collected from the supermarkets around the city of Riyadh and transported in plastic bags to the environmental research laboratory at AL imam Mohammad Ibn Saud Islamic University for elemental analysis. Samples were dried and after drying, samples were grained into a fine powder using a ceramic mill and stored in polyethylene bags until used for acid digestion.

Chemicals and Reagents
All the standard stock solutions of heavy metals were certified reference materials that were purchased from agilent technologies (USA). HNO 3 and H 2 O 2 were heavy metal analysis grade and purchased from Wako Chemical Co. (USA). Reagent water, toluene and acetone were of analytical reagent grade and purchased from J.T. Baker (USA).

Acid Digestion of Samples
About 10 mL, high purity HNO 3 and 2 mL hydrogen peroxide were added to the beaker containing 2 g of dry 2 g of dry samples were placed in the fume cupboard for two days for digestion. The mixture was then digested at 80°C till the transparent solution was achieved. After cooling, the digested samples were filtered using Buchner funnels and the filtrate was diluted to 50 mL with distill water. The final solution were used for the elements analysis namely Cd, Cr, Cu, Fe, K, Mg, Mn, Ni, Pb, Zn, As, Se and Al by ICP optical emission spectrometer.

Spectrometric Analysis
The measurements were performed using a GENESIS ICP optical emission spectrometer (SPECTRO Analytical Instruments, Kleve, Germany) with axial plasma observation. The instrument includes a Paschen-Runge mount spectrometer, constructed employing the Optimized Rowland Circle Alignment (ORCA) technique. It consists of two hollow section cast shells, designed for direct thermal stabilization and small volume. 15 pre-aligned linear CCD detectors are installed on the outside of the optics body, which allow fast, simultaneous spectrum capture of the wavelength range between 175 and 777 nm. For UV access (<200 nm), the optical system purged with argon. The purge rate during normal operation is 0.5 L min −1 . To enable method transfer between individual instruments, Intelligent Calibration Logic (ICAL) was used to normalize the wavelength and the intensity scale of the optical system to a reference optic ("optic master"). Stability of the forward power in the case of rapidly changing sample loads was achieved through use of an air-cooled ICP-generator, based on a free running 27.12 MHz system. All ICP operating parameters were software controlled. The ICP-OES instrument was initialized and allowed to achieve thermal equilibrium over 30 min. Multi-element Solution Standards obtained from Agilen technology were used to calibrate and quantitate sample results. The Lower Detection Limit of the system (LDL) was calculated and found to be 0.00001 mg kg −1 on the average. ICP-OES Science Publications AJES determinations of elements concentration were performed using the emission lines 228. 802, 267.716, 324.752, 238.204, 766.490, 285.213, 259.372, 231.604, 220.353, 213.857, 189.641, 196.090 and 384.401 λ (nm) for the elements Cd, Cr, Cu, Fe, K, Mg, Mn, Ni, Pb, Zn, As, Sea nd Al respectively.

RESULTS
The concentration of the elements Cu, Zn, Fe, Cr, Mn and Ni are presented in Table 1 and concentration of Cd, Al, Pb, As and Se are presented in Table 2

DISCUSSION
Cd, Cr, Cu, Fe, K, Mg, Mn, Ni, Pb, Zn, As, Se nd Al were chosen as representative metals whose levels in the environment represent a reliable indicator of environmental contamination metals such as Cu, Fe, K, Mg, Mn, Ni, Zn and Se are essential metals since they play an important role in biological systems, whereas Al and Pb, Cd and As are non-essential metals as they are toxic even in low concentration. The order of trace elements concentration in different type of canned foods obtined are Fe Se>Zn>Mn>Ni>Cu>Cr. The essential metals can also produce toxic effects when the metal intake is high concentration (Al-Khlaifat and Al-Khashman, 2007). According to the WHO recommendation, the daily intakes of the element of Fe Se, Zn, Mn, Ni, Cu and Cr in the current study fall far below than the legal limit set by the WHO/FAO (Joint FAO/WHO, 2011). Up on comparing the average concentration of Cu, Zn, Ni in this survey with similar data reported in previous study in Saudi Arabia 2006 Cu ( 0.27 mg k −1 ), Cr(0.3 mg k −1 ), Ni (23 mg kg −1 ). It was found that the concentration of such elements in my study was lower than those that we compare.The average value for Pb obtained from the result were lower than the maximum level of Pb 0.5 mg kg −1 permitted by ( Joint FAO/WHO, 2011) worldwide data 0.59, 0.28, 0.35, 0.011 mg kg −1 reported by (Tariq et al., 1993;Voegborlo et al., 1999;CIFA, 1992;Mani et al., 2012). Average value of As concentration reported in the current survey less than the legal limit adopted by the FAO/WHO.Cd was detected 3 samples out of 13, all within acceptable levels set by (Joint FAO/WHO, 2011) 0.5 mg kg −1 . Aluminum is not considered to be an essential element in humans. The aluminum average value fall far below the permissible daily intake 60 mg day −1 (FAO/WHO, 1989). The regression analysis has shown that significant correlation was noted between Se and As concentration as shown in (Fig. 2). On the other hand positive correlation was found between As and Pb (Fig. 3).

CONCLUSION
Based on the obtined result of the Elemental analysis of imported canned foods in the city of Riyadh the following conclusion can be drown: • No contamination have been observed in all samples analyzed • The essential elements concentration found to be in acceptable level • The toxic element concentration found to be within the acceptable recommended standard level given by FAO and WHO • Significant correlation was noted between Se and As • Positive correlation was noted between Mn and Ni • Positive correlation was noted between As and Pb

ACKNOWLEDGMENT
The auther would like to thank many colleagues at AL imam Mohammad Ibn Saud Islamic University for their valuable help with these experiments.