## 1 Introduction  
Cruciferous vegetables are a rich source of glucosinolates (GLs); a large and diverse group of chemicals with cancer chemoprotective properties [1]. When plant cells are damaged, e.g., by grinding or chopping, GLs are released and converted into isothi cyanates by the enzyme myrosinase (thioglucide glucohydrolase, EC3.2.3.1) [2]. Isothiocyanates are largely responsible for cancer chemoprevention and antioxidant [3; 4; 5]. Sulforaphane (4-methylsulfinbybutylisothiocyanate), derived from glucoraphanin (4-methylsulfinbybutylglucosinolate), is the most potent natural inducer of phase II (detoxification) enzymes, including quinone reductase and glutathione S-transferase [6] and has subsequently been shown to possess anticarcinogenic properties [7]. Erucin (4-methylthiobutyl isothiamate), derived from glucoerucin (4-methylsulfinlybutyl glucosinolate), has also shown promising anticancer effects in some in vitro and in vivo experiments [8; 9]. Unlike sulforaphane, erucin and glucoercuinc possess direct antioxidant behavior and are efficient scavengers of hydrogen peroxide and organic hydroperoxides. Therefore, we try to purify glucosinolate first and then produce isothiyanate [10].  
In the past few decades, GLs have been isolated and purified using solvent extraction and a variety of chromatographic techniques including: Alumina column chromatography [11]; low-pressure column chromatography [12]; preparative high-performance liquid chromatography [13]; preparative high-speed counter-current chromatography [14], ion-exchange chromatography on DEAE-Sephadex(r) A-25 [10; 15; 16]; strong ion-exchange centrifugal partition chromatography [17]; and slow rotary counter-current chromatography [18]. However, the complexity and high operational costs of these methods are inappropriate for the large quantities of GLs necessary to satisfy the increasing demands of research and commerce. Therefore, an efficient and economical industrial approach to obtain the product should be developed to meet these demands.  
GLs have good water solubility because of their ionized sulfate and hydrophilic \(\beta\)-D-thioglucose moieties [1]. Hence, macroporous ion-exchange resin adsorption [19] and alumina [12] have been used to isolate and concentrate GLs. Typically, an inorganic salt was used to desorb GLs from the ion-exchange resin; nanofiltration technology and precipitation with methanol were used to remove the salt from the isolated GLs. In a previous study, we found that precipitation with methanol could not remove inorganic salt completely [12]. Although nanofiltration technology could efficiently remove inorganic salt, it was not cost effective due to the specialized apparatus required. Therefore, it is necessary to develop an efficient and low-cost method to separate GLs without removing salt. Furthermore, large quantities of co-extracted pigments also compromised the purity of GLs. Until now, there have been few studies concerning the decolorization of the crude extracts of GLs from cruciferous vegetables.  
Growing attention has been paid to separating and purifying pharmaceutical and natural products using polymeric resins because of their availability, economy, high chemically stability, and recyclability [20]. The aim of this study was to evaluate the performance (absorption/desorption and decolorization) of macroporous adsorbent PGMA and its three amine modified (ethylenediamine, diethylamine, triethylamine) anion-exchange adsorbents (PGMA-I, PGMA-II, PGMA-III) for the purification of glucoercuinc from crude extracts of rocket seeds (_Eruca vesiculara_). Adsorbents that decolorized pigments and adsorbed/desorbed glucoercuinc most efficiently were selected, and separation parameters optimized for purification efficiency.