RP‐HPTLC Application in the Investigation of Solubility in Water of Long‐Chain Fatty Acids

Abstract Acids, from octanoic to octadecanoic, have been separated using RP‐HPTLC, on RP‐18 plates without and with a concentrating zone, using methanol‐water and ethanol‐water (90∶10 and 95∶5, v/v) as mobile phases. RF values obtained have been converted to RM values. RM values have been used to calculate the solubilities in water of fatty acids investigated at different temperatures. Relationships between solubility in water of fatty acids at different temperatures and RM values obtained using RP‐HPTLC have been described by polynomials of third degree or expotential functions. All described relationships have been characterized by high values of determination coefficients, which were in the range of 96.65÷99.97%. This suggests the possibility of using them to calculate and predict the values of solubilities in water of acids investigated.

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