Schemes Of Solid-phase Spectrophotometric Analysis Of Food Objects

The aim of research is development of approaches to the development of schemes for microelement analysis of food objects. This will make it possible to monitor food quality by simple and affordable methods in factory laboratories.Based on data on the immobilization of dyes on ion exchangers and on the interaction of metal ions or their complexes with immobilized dyes, solid-phase spectrophotometric (SPS) and photometric methods for determining metal ions in food technology, biotechnology and the environment have been developed.Techniques are sensitive. High distribution coefficients (D³104 cm3/g) of metal ions help to reduce the detection limit when using immobilized dye as compared to the reaction in solution. Based on the detection limit values (DLV), the proposed sorption-spectrophotometric methods for determining metal ions are second only to the atomic absorption (AAS) determination of Cd (II) and Hg (II) ions and the polarographic determination of Cd (II) ions. However, the proposed methods for the determination of these metal ions are sufficient for the determination of Cd (II) and Hg (II) ions in food products at the MPC level. In the case of determination of Pb (II), Zn (II), Cu (II), Fe (III) ions, the developed methods have advantages over standard methods for determination of metal ions in food products, since they make it possible to determine these ions at a level ≤0.1…0.5 MPC;Ion exchangers with immobilized dyes and solid-phase spectrophotometric determination methods with their participation are environmentally safe, since they do not require the use of toxic organic reagents; are simple in execution and economically advantageous because of the low cost of used materials and reagents.The correctness of the results of the determination by the developed methods is proved: by comparison with the results of determinations on standard methods at various analysis objects using the method of additives, standard samples. The relative standard deviation of the developed SPS determination procedures does not exceed 0.10, which indicates satisfactory reproducibility of the results. The developed methods exceed the majority of standard and best analogs, known from the literature, for sensitivity and selectivity. The used methods of analysis are characterized by the simplicity of the experiment, ecological safety, do not require special expensive equipment, highly qualified personnel and a stationary laboratory

Determining the Microelement Composition of Poppy Seeds Using Solid­phase Spectrophotometry Method

Poppy seeds are one of the most important and oldest oil-bearing crops in the world. Therefore, quality control of poppy seeds and food products whose composition contains them as a food additive, is very important. To this end, we have applied procedures for solid-phase spectrophotometric and photometric determining of micro elements in food products.It was established that in determining cadmium and zinc, the best ion exchanger for the group concentration of interfering metal ions is the ion exchanger with the immobilized KO. made it possible to concentrate and determine in the solid phase the ions of Hg(II). Using enabled selective determining of Pb(II).Selective determining of the Fe(III) ions at pH 3 was conducted using ammonium thiocyanate. Cu(II) was determined photometrically upon masking the ions of Fe(III) employing SPADNS. Based on the data acquired, we have developed a microelement analysis scheme for poppy seeds.It was established that the sample contained, mg/kg: Cu(ІІ) – 5.0; Pb(ІІ) – 0.3, Zn(ІІ) – 50, P(V) – 1,600, K − 550, Na – 20, Ca – 1,500, Mg(II) – 450; Fe(ІІІ) −10; Cd(ІІ) and Hg(ІІ) are absent.The proposed scheme for analysis of poppy seeds is universal and could be applied for microelement analysis of other food products.The procedures employed are characterized by sensitivity and selectivity.Ion exchangers with the immobilized dyes, as well as procedures for the solid-phase spectrophotometric determining, are environmentally safe. They do not require the use of toxic organic reagents.The procedures applied are easy to use.Relative standard deviation in the results does not exceed 0.10. This indicates good reproducibility of the results