The use of atomic absorption spectroscopy for the determination of calcium in dairy products

Abstract

Introduction: Calcium is a mineral present in the highest quantity in the human body and has several important functions. Over 99% of total body calcium is in the bones and joint, which are designed to support the structure. The remaining 1% is present in the blood, muscle and intercellular fluids. Dairy products are the best sources of calcium in the diet, therefore, the health authorities recommended to drink three glasses of milk per day. The calcium content in dairy products is different depending on several factors.

The purpose of this study is a quantitative assessment of calcium in various milk products using a contemporary instrumental method - atomic absorption spectroscopy (AAS). The basic principle of atomic absorption measurements is background radiation attenuation due to absorption in the sample atomized. Relationship between initial and attenuated radiation gives information about the concentration of the element in the test sample.

Materials and methods: 1% fat milk, 2% fat yogurt, skimmed yogurt, atomic absorption spectrometer ICE 3300, lanthanum oxide, calcium carbonate, tableware and household utensils laboratory. Evaluation of the calcium content was carried out based on the standard curve.

Results and discussions: Samples for analysis were prepared by homogenization of the products under study with lanthanum oxide solution 10% dilution without extraction with mineral acids. The calibration curve was linear one, characterized by the regression equation y = c + 0.1999 0.4085 • coefficient of correlation r = 0.9997. The calcium content in milk was 987,62mg / l, yoghurt 2% - 1104.76 mg / L, skimmed yogurt-1095.23 mg / l. The results were compared with references and shows an acceptable correlation values. Considering the compromise made between cost and required sensitivity, flame AAS technique can be considered suitable for the determination of calcium.

Conclusion: It was used a simple method for preparing samples for spectroscopic measurements that allowed precise evaluation of the calcium in dairy products. The method can be recommended for routine analyzes.