Study on analytical methods for quantifying the non‐adsorbed reactive dye forms in an exhausted dyebath

Abstract

Reported herein are the results of an analysis of the compatibility of three methods for quantifying the non-adsorbed forms of reactive dyes, in an exhausted dyebath, of the type monochlorotriazine ⁄ b-sulphatoethylsulphone used in dyeing cellulosic fibres (cotton). The first method is based on spectrophotometric analysis and involves measuring the absorbance of the residual dyebath (after the dyeing process), the second is based on colorimetric analysis and involves measuring the reflectance of the dyed fabric and the third is based on high-performance liquid chromatography. The purpose of the latter is to identify and quantify the non-adsorbed dye forms in the residual dyebath. The calculated exhaustion values unequivocally prove the reliability and compatibility of these methods.

The Identification of Cotton Fibers Dyed with Reactive Dyes for Forensic Purposes

“…For this reason, sensitive analytical methods must be applied for the identification of reactive dyes isolated from dyed cotton fibers. Table 3 and Table 4 show the methods developed for the identification of reactive dyes based on chromatographic techniques [ 14 , 35 , 36 , 37 , 39 , 43 , 44 , 45 , 46 ]. A description of the chromatographic conditions is included in Table 3 ; the selected qualification and quantification parameters are in Table 4 .…”

“…High-performance liquid chromatography (HPLC) coupled with spectrophotometric detectors such as UV-Vis [ 43 ] and diode array (DAD) [ 35 , 36 , 37 , 39 , 44 , 45 ], as well as coupled with high-resolution mass spectrometric (HRMS) [ 35 , 36 , 37 , 39 ] and tandem mass spectrometric (MS/MS) detectors [ 46 ] was the most often used technique for the identification of reactive dyes for forensic purposes ( Figure 9 , Table 3 and Table 4 ). Usually, the HPLC-MS apparatus was equipped with both detection systems [ 35 , 36 , 37 , 39 ] ( Figure 9 ; Table 3 and Table 4 ).…”

“…Usually, the HPLC-MS apparatus was equipped with both detection systems [ 35 , 36 , 37 , 39 ] ( Figure 9 ; Table 3 and Table 4 ). Chromatographic analyses were usually performed using reverse-phase C18 columns [ 35 , 39 , 43 , 44 , 45 , 46 ] of a length from 50 to 150 mm. On the other hand, Carey et al and Schotman and co-workers applied a Grom-sil 120 ODS-5 ST chromatographic column with a length of 150 mm [ 36 , 37 ].…”

“…On the other hand, Carey et al and Schotman and co-workers applied a Grom-sil 120 ODS-5 ST chromatographic column with a length of 150 mm [ 36 , 37 ]. In most cases, the chromatographic separation of reactive dyes was carried out under gradient programs using such mobile phases as an ammonium formate aqueous phase and formic acid in water (pH 4): a ratio of 70/30 methanol/acetonitrile organic phase [ 35 ]; ammonium acetate in water/methanol (95/5): ammonium acetate in acetonitrile/methanol (50/50) [ 36 , 37 ]; ammonium formate and formic acid in water (pH 4): methanol/acetonitrile (70/30) [ 39 ]; ammonium acetate in water/acetonitrile (90/10) (pH 6): ammonium acetate in water/acetonitrile (10/90) [ 44 , 45 ]; acetic acid with water/acidified acetonitrile [ 46 ]. In one case, the isocratic conditions using a 47:53 v/v mixture of acetonitrile and ammonium acetate buffer containing trimethylammonium bromide (CTAB) as an ion-pairing agent was applied [ 43 ].…”

“…Chemchame and co-workers also studied the hydrolysis of reactive dyes ( Table 3 and Table 4 , Methods No 7 and No. 8) [ 44 , 45 ]. In these studies, four standard dye solutions of heterobi-functional reactive dyes containing monochlorotriazine/β-sulfatoethylsulfone (C.I.…”