Comparison of the Detection Limit and the Quantification Limit of Nicotinamide on Different Chromatographic Sorbents in TLC

TLC combined with densitometry was successfully applied to determine the Detection Limit (LOD) and also Quantification Limit (LOQ) of nicotinamide. Average values of LODs and LOQs were determined on the basis of the standard deviation of the response and the slope of specific calibration curve according to the procedure recommended by ICH guideline. Influence of chromatographic conditions such as stationary phase (sorbent) and also mobile phase composition on determining of LOD and LOQ values of examined nicotinamide by NP-TLC and RP-TLC systems was estimated. Of all chromatographic plates and mobile phases used, those which give the best results (the lowest LOD and LOQ values) by NP-TLC system is silica gel 60F254 plates developed with methanol as mobile phase: LOD=0.088 μg/spot, LOQ=0.265 μg/spot. In the case of RP-TLC method the three of four applied mobile phases: dioxane, methanol, and ethanol enable detection of nicotinamide at the lowest level on chromatographic plates precoated with RP18F254: LOD ranges from 0.077 to 0.183 μg/spot. The LOQ value is placed in the range from 0.233 to 0.553 μg/spot.The results of LODs and LOQs indicate that the proposed TLC-densitometric method is suitable for the detection and also quantification of nicotinamide at different level.