Simultaneous determination of individual isothiocyanates in plant samples by HPLC-DAD-MS following SPE and derivatization with N-acetyl-l-cysteine

Tadeusz Pilipczuk; Barbara Kusznierewicz; Tomasz Chmiel; Witold Przychodzeń; Agnieszka Bartoszek

doi:10.1016/j.foodchem.2016.07.125

Simultaneous determination of individual isothiocyanates in plant samples by HPLC-DAD-MS following SPE and derivatization with N-acetyl-l-cysteine

Food Chem. 2017 Jan 1:214:587-596. doi: 10.1016/j.foodchem.2016.07.125. Epub 2016 Jul 21.

Authors

Tadeusz Pilipczuk¹, Barbara Kusznierewicz¹, Tomasz Chmiel¹, Witold Przychodzeń², Agnieszka Bartoszek³

Affiliations

¹ Department of Food Chemistry, Technology and Biotechnology, Faculty of Chemistry, Gdańsk University of Technology, Narutowicza 11/12, 80-233 Gdańsk, Poland.
² Department of Organic Chemistry, Faculty of Chemistry, Gdańsk University of Technology, Narutowicza 11/12, 80-233 Gdańsk, Poland.
³ Department of Food Chemistry, Technology and Biotechnology, Faculty of Chemistry, Gdańsk University of Technology, Narutowicza 11/12, 80-233 Gdańsk, Poland. Electronic address: agnieszka.bartoszek@pg.gda.pl.

PMID: 27507514
DOI: 10.1016/j.foodchem.2016.07.125

Abstract

The procedure for the isothiocyanates (ITCs) determination that involves derivatization with N-acetyl-l-cysteine (NAC) and separation by HPLC was developed. Prior to derivatization, plant ITCs were isolated and purified using solid-phase extraction (SPE). The optimum conditions of derivatization are: 500μL of isopropanolic eluate obtained by SPE combined with 500μL of derivatizing reagent (0.2M NAC and 0.2M NaHCO3 in water) and reaction time of 1h at 50°C. The formed dithiocarbamates are directly analyzed by HPLC coupled with diode array detector and mass spectrometer if required. The method was validated for nine common natural ITCs. Calibration curves were linear (R(2)⩾0.991) within a wide range of concentrations and limits of detection were below 4.9nmol/mL. The recoveries were in the range of 83.3-103.7%, with relative standard deviations <5.4%. The developed method has been successfully applied to determine ITCs in broccoli, white cabbage, garden cress, radish, horseradish and papaya.

Keywords: Brassicaceae; Dithiocarbamates; HPLC-DAD-MS; Isothiocyanates; N-acetyl-l-cysteine; SPE.

MeSH terms

Acetylcysteine / chemistry*
Chromatography, High Pressure Liquid / methods*
Chromatography, Liquid / methods*
Isothiocyanates / chemistry*
Mass Spectrometry / methods*
Plants / chemistry*
Solid Phase Extraction / methods

Substances

Isothiocyanates
Acetylcysteine