Use of anion exchange membrane extraction for the high pressure liquid chromatographic analysis of mustard seed glucosinolates
Szmigielska, A.M. and J.J. Schoenau, . 2000. J. Agric. Food Chem. 48: 5190-5194
Abstract
A new one-step extraction using anion-exchange membranes for the HPLC determination of glucosinolates in mustard seeds is reported. The exchange of glucosinolates on the
membranes was studied using sinigrin in solutions and sinigrin added as an internal standard to seeds of yellow
mustard. By varying time of extraction, membrane size, and sample size, the optimal conditions for maximum
glucosinolate recovery were determined and the following
procedure was adopted: 0.2 g of ground mustard seeds are
heated in 20 mL of boiling water for 5 min. After cooling, samples are transferred to plastic centrifuge
tubes, 9-cm2 membranes are added, and suspensions are shaken on a mechanical shaker for 2.5 h. Glucosinolates are then eluted from the membranes with 25 mL of 1 N KCl by shaking again for 2.5 h. Using this
procedure, the sinigrin extraction from solutions and from mustard seeds was linear with 80% recovery. Seeds of
yellow, brown, oriental, and Indian mustard were analyzed
by this procedure; excellent reproducibility, with coefficients of variation in the range 1.0- 4.3% were obtained. This method offers a simple and inexpensive alternative to complicated and tedious procedures for glucosinolate isolation/purification required for chromatographic determinations.
Key Words
Glucosinolates, mustard seed, extraction, high-performance liquid chromatography
