Development of a simple analytical method for determining trihalomethanes in beer using a headspace solid-phase microextraction technique

Abstract

Recebido em 11/2/13; aceito em 14/3/13; publicado na web em 13/6/13We developed a simple, rapid, and solventless method for analyzing trihalomethanes in beer samples using headspace solid-phase microextraction. The effects of varying experimental parameters, such as extraction temperature and time, addition of sodium chloride, and agitation speed, on extraction yield were studied using a univariate experimental design. Limits of detection between 0.22 and 0.46 μg L -1 and wide linear ranges were achieved for trihalomethanes. We measured the trihalomethane recoveries and precision (as the standard deviation of repeat measurements) and demonstrated the applicability of the proposed method by analyzing 32 beer samples.

How the Inclusion of Treated Water in Beverages Influences the Appearance of Halogenated Volatile Organic Compounds

“…In the bibliography, different solventless techniques have been employed for the determination of several VOCs and THMs in beverages and foods. All of these methodologies have been proposed only for the four common THMs and do not reach the sensitivity of the proposed method. ,− In addition, some of these methodologies involve the manipulation of the beverages by dilution/centrifugation/heating in water baths, etc., with the consequent loss of volatile compounds. More recently, the four THMs have been determined in soft drinks and beers, but the method is ca.…”

“…More recently, an HS-SPME method has been applied to determine four THMs in soft drinks 22 and beer. 23 In general, these methods require manual sample manipulation with low sensitivity because they are adapted from water methodologies. The aims of this work were (i) to develop a solventless SHS-GC−mass spectrometric method with enough sensitivity to determine target analytes at nanogram per liter levels in beverages; (ii) to include six emerging iodinated THMs for the first time, in addition to the four common THMs and four VOCs regulated in treated water; and (iii) to discriminate the source of these species through treated water employed for beverage preparation or by contamination through the industrial process (i.e., washing, bottling line, etc.…”

“…Other HS–solid phase microextraction (SPME) or purge-and-trap GC methods require the dilution or centrifugation of beverages, which produces a loss of the species through volatilization. More recently, an HS-SPME method has been applied to determine four THMs in soft drinks and beer . In general, these methods require manual sample manipulation with low sensitivity because they are adapted from water methodologies.…”