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A simple and very sensitive method for the spectrophotometric determination of manganese in pharmacological preparations and vegetable fertilizers is proposed. The method is based on the formation of a blue coloured complex of Mn (II) with 9-phenyl-2,3,7-trihydroxy-6-fluorone (PF) in the presence of cetylpyridinium chloride (CP) and Triton X-100. Optimum concentrations of PF, CP, Triton X-100 and pH ensuring maximum absorbance were defined. The complex Mn(II)-PF-CP-Triton X-100 shows maximum absorbance at 591 nm with the molar absorptivity value 1.77x10(5 )L mol(-1 )cm(-1). The detection limit of the method is 0.004 microg mL(-1). The Beer's law is obeyed for manganese concentrations in the range 0.02-0.2 microg mL(-1). The effect of foreign ions was elucidated. The statistical evaluation of the method was carried out for six determination using 5 microg Mn and the following results were obtained: standard deviation 0.021, confidence interval 5.05+/-0.05 microg Mn. The method has been applied for the determination of manganese in pharmacological preparations (Biovital, Kinder Biovital) and vegetable fertilizers (Hydrovit 100, Florovit).

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A simple and quick method of durable samples preparation by the thin layer method through direct digesting of the analysed material on the substrate has been presented. Four-and three-component mono-and polycrystals have been analysed. Standards have been used in calibration containing: Cr, Co, Ni, Cu, Zn, Ga, Se, Sb, Yb. To improve the correlation between the concentration and the¯uorescent radiation models of mathematical corrections have additionally been used: multiple linear regression, Lucas-ToothPyne model (L. T. P.) and de Jongh model (d. J.).Statistical parameters: detection limits for 0.5 mg samples: Cr±0.041%, Co±0.034%, Ni±0.042%, Cu± 0.053%, Zn±0.054%, Ga±0.057%, Se±0.057%, Sb± 0.113%, Yb±0.077%. Correlation coef®cients: simple regression 0.9946±0.9997, multiple regression 0.9974±1.0000, L. T. P. 0.9993±1.0000, d. J. 0.9995± 1.0000.