Determination of Mineral Content in Indian Spices by ICP-OES

Vegetarian and non vegetarian Indian diet consists of various cereals and vegetables along with spices, often used in the preparation of curries. The nutritive potential of trace element has been evaluated using Inductively coupled plasma optical emission spectrometry (ICP-OES). In this study, 15 trace elements like As,Hg,Se,Zn,P,Pb,Cd,Fe,Mn,Cr,Mg,Cu,C,Na and K have been determined in Five Indian popular spices. The result shows that the spice Aniseed contains Phosphorous (2027.10±14.0 mg/kg), Iron (5.40±2.0 mg/kg), Magnesium (270.10±7.0mg/kg), Calcium (602.8±4.0 mg/kg), Sodium (365.10±3.0 mg/kg) and Potassium (887.80±11.0 mg/kg). The spice Poppy seeds showed Phosphorous content of (3980.0±13.5mg/kg), Iron (5.475±2.5 mg/kg), Magnesium (287.20±14.0 mg/kg), Calcium (690.50±4.0 mg/kg), Sodium (81.16±5.0 mg/ kg) and Potassium (746.70±6.0 mg/kg). The spice Cloves showed that it contains Phosphorous (6355.0±20.0 mg/kg), Iron (1.699±0.2mg/kg), and Potassium (318.01±5.0 mg/kg). The spice Ajwain seeds showed the presence of Phosphorous (1764.0±16.0 mg/kg), Iron (17.87±8.0 mg/kg), Manganese (5.729±2.6 mg/kg) and Calcium (1353.0±10.0 mg/kg), The spice Fenugreek seeds showed that it contains Phosphorous (2950.0±17.5 mg/kg) and Potassium (124.82±2.0 mg/kg). Heavy metals As and Hg are absent in all five spices. Heavy metals Cr, Cd and Pb are absent in Cloves, Fenugreek and Ajwain species. The results showed that the spice powder is a good source of calcium, potassium, magnesium, Iron and Phosphorous.


INTRODUCTION
Spices refer to all of the edible parts of a plant used for flavoring or coloring foods, including fruit, seed, root, bark or vegetable substance 1 .Some are often used as preservative against the action of harmful bacteria or prevents their growth 2 .The specific uses of spices tend to vary considerably among cultures and countries, medicine, religious rituals, cosmetics, perfumery and in foods.As food, economic status.Indian curry is spiced with salt, red chilies and other spices, such as turmeric & coriander powder, depending on individual taste and other considerations.Besides, condiments such as cloves, black pepper, cardamom and bay leaves are also used to spread over cooked/fried rice and curry preparations.
Several workers have discussed the constituents of these spices in terms of their volatile oils and other vitamin contents 5,6 and have reported various characteristics for determination of chemical and toxic constituents of Indian spices.Ila and Jagam 7 reported 24 elements in six Indian spices.Abou-Arab and Abou-Donia 8 have determined heavy metal contaminants in Egyptian spices.
The used methodologies had been either time consuming and costly, or importantly did not allow simultaneous estimation of the micro minerals concerned.Inductively coupled plasma optical emission spectrometry (ICP-OES) is well established as a method for multi elemental analysis and the determination of isotope ratios 9 and overcomes many of these problems.This methodology allows simultaneous analysis of a wide range of trace elements in the same sample and has been used in this study.
The objective of the present study was the analysis of trace element (As, Hg, Se, Zn, P, Pb, Cd, Fe, Mn, Cr, Mg, Cu, Ca, Na and K) levels in the dehydrated powder of Indian spice powder using inductively coupled plasma optical emission spectrometry (ICP-OES).

MATERIAL AND METHODS
The analysis of minerals in the following spices were used in this study Aniseed (Pimpinella anisum), Poppy seed (Papaver somniferum), Cloves (Syzygium aromaticum) Fenugreek seeds (Trigonella foenum-graecum) and Ajwain (Trachyspermum ammi) powder samples and they were obtained from a local supermarket and tested by using ICP-OES method (10).All minerals and heavy metals measurements were carried out using the Perkin Elmer optima ICP-OES (Model: OPTIMA 2000DV, serial number: 080N3041701) and the ICP-OES operating conditions are listed in table 1.

Reagents and chemicals
Analytical reagents-grade chemicals were used in the preparation of all solutions.All the plastic and glassware were cleaned by soaking in dilute nitric acid (1 + 9) and were rinsed with distilled water prior to use.Nitric acid (65%) and hydrogen peroxide (30%) were supplied by Merck (India)

Sample preparation
The samples were digested using microwave digestion method (Model: ETHOS One, Make -Milestone).The samples of approximately 1.0 g were digested with 6 ml of HNO3 and 2 ml of H2O2 in microwave digestion system.The samples and acid mixture are placed in suitably inert polymeric microwave vessels.The vessel is sealed and heated in the microwave digestion system.The temperature program was as follows: 2 min for 400 w, 6 min for 400 w, 5 min for 400 w, 8 min for 800 w and 8 min for vent.The resulting solutions were cooled and diluted to 10 ml with distilled water.The determination of metal contents in this clear solution was carried out by Inductively coupled plasmaoptical emission spectrometry (ICP-OES).

ICP-OES (Inductively Coupled Plasma-Optical Emission Spectrometry) Analysis of Samples
All samples were analyzed in triplicates by ICP-OES Perkin-Elmer; model Optima™ 2000 DV, using winLab32 software for the analysis.The analytical measurements were made with a simultaneous Perkin-Elmer ICP OES, model optima 2000DV, winLab32™, version 7.0 software equipped with a peristaltic pump, a cross-flow nebulizer (coupled to a ryton double pass spray chamber) and a ceramic central torch tube injector with an internal diameter of 2 mm.The operating parameters are listed in Table 1.The wavelengths, measurement parameters and standards for each element are given in Table 2.

Analysis of certified reference material (CRM) of Minerals and calibration
Aliquots of ICP multielement standard solution (10 to 50 mg/L Merck) containing the elements such as (As, Hg, Se, Zn, P, Pb, Cd, Fe, Mn, Cr, Mg, Cu, Ca, Na and K) were used in the preparation of calibration solutions.Working standard solutions were prepared by dilution of the stock standard solutions to desired concentration in 1% HNO3.The ranges of the calibration curves (5 points) were selected to match the expected concentrations for all the elements of the sample studied by ICP-OES.The correlation coefficient r 2 obtained for all cases was 0.9999

CONCLUSIONS
From the results, it is seen that elements like As, Hg, Se, Zn, P, Pb, Cd, Fe, Mn, Cr, Mg, Cu, Ca, Na and K were successfully estimated in the Indian spice powder samples by using ICP-OES with microwave digestion procedures.The use of ICPOES provides a simpler, effective, faster, and less contamination procedure of determining the quality of spice extracts.The results show that spice powder is a good source of calcium sodium, potassium, magnesium, selenium and Phosphorous and spice was a very important human nutrient since their consumption has increased in recent years.Heavy metals in spice are a problem for human consumption and hence a detailed study of minerals in spices is needed.Heavy metals As and Hg are absent in all five spices.Heavy metals Cd, Cr and Pb are absent in Fenugreek, Cloves and Ajwain spices.