|Title||Rapid Analysis of Illegal Cationic Dyes in Foods and Surface Waters Using High Temperature Direct Analysis in Real Time High-Resolution Mass Spectrometry|
|Author(s)||Wen, Ruizhi; Zeng, Dong; Yang, Zihui; Jiang, Le; Ma, Ming; Chen, Bo; Beek, Teris A. Van|
|Source||Journal of Agricultural and Food Chemistry 66 (2018)28. - ISSN 0021-8561 - p. 7542 - 7549.|
Laboratory for Organic Chemistry
|Publication type||Refereed Article in a scientific journal|
|Availibility||Full text available from 2019-07-18|
|Keyword(s)||crystal violet - direct analysis in real time - food safety - high-resolution mass spectrometry - illegal cationic dyes - induced phase separation extraction - malachite green - methylene blue - rhodamine B|
A high temperature desorption (HTD) direct analysis in real time-high-resolution mass spectrometric (DART-HRMS) method was developed for the rapid analysis of four banned cationic dyes. Rhodamine B is used to dye foods, while malachite green, crystal violet, and methylene blue are added to fishponds as antimicrobials. A simple induced phase separation extraction was used to pretreat samples. The DART-HRMS method employed two temperature steps, i.e., 200 °C for drying, purification, and enrichment of sample solution and 500 °C for thermal desorption and ionization of analytes. The calibration curves of dyes in the range of 50-2000 ng/mL were linear using deuterated malachite green as an internal standard. The LODs vary for all analytes between 0.1 and 30 ppb depending on the matrix and experimental conditions. Through analyses of real samples, two chili powders and one chili oil were found to be contaminated by rhodamine B. The concentrations were comparable with those found by an HPLC-MS/MS method.