Influence of Chromatographic Conditions on LOD and LOQ of Fluoxetine and Sertraline Analyzed by TLC-Densitometric Method

Abstract

This research introduces the analysis of fluoxetine and sertraline by means of the TLC-densitometric method. They provide information on LOD and LOQ under various chromatographic conditions. The study used adsorption (NPTLC) and partition (RPTLC) thin-layer chromatography in combination with a densitometric analysis. Four types of chromatographic plates precoated with: silica gel 60 F254, silica gel 60, silanized silica gel 60 F254 (RP-2), and a mixture of silica gel 60 and kieselguhr F254, as well as three mobile phases: chloroform + methanol + ammonia (9:1:0.4, v/v/v), chloroform + methanol + glacial acetic acid (5:4:1, v/v/v), and acetone + toluene + ammonia (10:9:1, v/v/v), were used in NPTLC. RP-18F254 and silanized silica gel 60 F254 (RP-2) plates and four mobile phases: methanol + water (10:0 and 9:1, v/v), acetone + water (10:0 and 9:1, v/v), were used in RPTLC. The lowest LOD and LOQ values for fluoxetine were obtained using a silanized silica gel 60 F254 (RP-2) with acetone + toluene + ammonia (10:9:1, v/v/v) in NPTLC, and with a silanized silica gel 60 F254 (RP-2) in combination with methanol + water (10:0, v/v) in RPTLC. The lowest LOD and LOQ values of sertraline were obtained using a silica gel 60 with acetone + toluene + ammonia (10:9:1; v/v/v) in NPTLC. The smallest amount of sertraline was detected on the silanized silica gel 60 F254 plate in combination with methanol + water (9:1, v/v) in RPTLC. The obtained results provide important information that can give a good basis and set the direction for further, more detailed research; the results can also benefit other researchers who analyze fluoxetine and sertraline with the TLC technique in model systems (testing standards) as well as in drug and biological samples.

Biosensing Basics

“…The blank and calibration curves represent distribution functions for limit of decision and sample measurements, respectively. They overlap within a statistically defined limit, resulting in the lowest value on the calibration curve with LOD, which is the minimal detectable value by projection to the X-axis in concentration [63][64][65].…”

Glucose sandwich assay based on surface-enhanced Raman spectroscopy

“…According to the results shown in Fig. S7, † the limit of detection (LOD) for histamine was estimated to be 8.34 × 10 −12 M (S/N = 3), 40,41 with each characteristic peak of the probe molecule being identified unambiguously. Simultaneously, 10 −6 -10 −10 M glucose was prepared to establish a linear relationship, and the correlation coefficient was 0.9886, demonstrating that glucose concentration can be detected accurately by our substrate.…”