US EPA

1036207 

Journal Article 

Ultrasonic enhancement of leaching and in situ derivatization of haloacetic acids in vegetable foods prior to gas chromatography-electron capture detection 

Alvarez Sánchez, B; Priego Capote, F; Luque de Castro, MD 

2008 

Yes 

Journal of Chromatography A
ISSN: 0021-9673
EISSN: 1873-3778 

1201 

1 

21-26 

English 

18586256 

10.1016/j.chroma.2008.06.011 

WOS:000258112300003 

A continuous ultrasound-assisted approach to enhance the extraction of nine haloacetic acids (HAAs) from vegetables with in situ derivatization to methyl esters for their gas chromatography (GC) analysis is presented. The optimization of simultaneous extraction (using acidic methanol as extractant) and derivatization enabled the completion of both steps in 15 min. Ultrasound assistance has proved to enhance both linked steps, which results in a considerable shortening of the overall analysis time (i.e. 552.1 and 552.2 EPA methods for analysis of these compounds in drinking water require 1 and 2 h, respectively, only for derivatization). After sample preparation, the esterified HAAs were isolated by liquid-liquid extraction with n-hexane and analysed by GC-electron capture detection. The proposed method is an interesting alternative to present methods for the determination of HAAs in vegetable foods. This is an area unjustifiably forgotten by reference laboratory organisms as proved by the absence of official methods for analysis of the target compounds in these samples. The proposed method can be applied to the analysis of HAAs in any solid sample after optimization of the main variables involved in the extraction-derivatization step. 

Gas chromatography-electron capture detection; Haloacetic acids; Sample preparation; Solid samples; Ultrasound-assistance