Determination of Some Textile Dyes in Wastewater by Solid Phase Extraction Followed by High-Performance Thin-Layer Chromatography

The objective of this paper is to report a procedure for the extraction and the determination of five textile dyes (Lanasyn Blue F-L 150, Lanasyn Dark Brown M-GLN, Lanasyn Red M-GA, Nylosan Dark Brown S-MBL, and Nylosan Red N-2RBL) which were not yet studied in literature by high-performance thin-layer chromatography. For SPE of these dyes, four types of Strata cartridges (WAX/NH2, SAX, C18-U and C18-E) were tested. The best results were obtained on Strata WAX/NH2. The dyes were separated on precoated Alugram RP-18W/UV254 plates with the n-butanol-ethyl acetate-5% ammonium hydroxide 4:4:1 (v/v) mobile phase. The densitometric scanning was performed at 550 nm. Linear regression analysis of the calibration data indicated a good linear relationship between the peak area and the dye concentration in the range of 20–60 ng per band. For the HPTLC method, the detection and the quantification limits of the studied dyes were calculated. The obtained detection limits (ng per band) were: 6.6 for Lanasyn Blue F-L 150, 5.90 for Lanasyn Dark Brown M-GLN, 3.38 for Lanasyn Red M-GA, 5.49 for Nylosan Dark Brown S-MBL, and 1.07 for Nylosan Red N-2RBL. The SPE-HPTLC procedure was applied to monitor these textile dyes in the effluent wastewater samples collected from a textile factory from Romania.