Formation of trihalomethanes in foods and beverages

Abstract

Trihalomethanes (THMs) are suspected carcinogens and reproductive toxicants commonly found in chlorinated drinking water. This study investigates THM formation during the preparation of beverages and foods using chlorinated drinking water. A total of 11 foods and 17 beverages were tested. Under the experimental conditions, each food and beverage formed THMs, primarily chloroform, although low or trace levels of brominated THMs were also detected. Tea formed the highest THM levels (e.g., chloroform levels from 3 to 67 microg l(-1)), followed by coffee (from 3 to 13 microg l(-1)), rice (9 microg l(-1)), soups (from 0.4 to 3.0 microg l(-1)), vegetables (<1 microg l(-1)), and baby food (<0.7 microg l(-1)). Chloroform formation with instant tea, used as a highly reproducible model system, increased with free chlorine concentration, decreased with higher food (tea) concentration, and was unaffected by reaction (steeping) time and bromide ion concentration. These findings indicate that chlorine-food reactions are fast, but that formation decreases as the chlorine demand of the food system increases. THMs are formed in the preparation and cooking of a wide variety of foods if free chlorine is present, and our results suggest that tea can be a significant source of exposure to THMs.

Safe Drinking Water? Effect of Wastewater Inputs and Source Water Impairment and Implications for Water Reuse

“…Exposure through ingestion includes not only contaminants in drinking water but also when tap water is used to make other drinks, such as coffee and tea, and when tap water is used in the cooking of foods. Foods can adsorb and concentrate DBPs and other contaminants (like solid-phase extraction materials) [128], and they can also be a source of precursors to form additional DBPs [129,130].…”

Static headspace–gas chromatography–mass spectrometry for the simultaneous determination of trihalomethanes and haloacetic acids in canned vegetables

“…Thus, THM levels (among other VOCs) have been found (2-450 g/kg) in a wide variety of beverages and foods [3], including vegetables such as beans [8], carrots, coleslaw, tomatoes [9] or dill pickles [10,11]. Other studies have focused on THM formation during the preparation of beverages and foods (including several vegetables), using ultrapure water with high concentrations of chlorine [12,13], or during the washing of the vegetable (baby spinach) with chlorine-based sanitizers [14]. The methods used in these studies include liquid-liquid extraction (LLE) and gas chromatography (GC) with electron capture detection (ECD) [8], purge-and-trap coupled to GC-mass spectrometry (MS) [9][10][11], static headspace (SHS)-GC-ECD [12,13] microextraction-GC-MS [14].…”

“…Other studies have focused on THM formation during the preparation of beverages and foods (including several vegetables), using ultrapure water with high concentrations of chlorine [12,13], or during the washing of the vegetable (baby spinach) with chlorine-based sanitizers [14]. The methods used in these studies include liquid-liquid extraction (LLE) and gas chromatography (GC) with electron capture detection (ECD) [8], purge-and-trap coupled to GC-mass spectrometry (MS) [9][10][11], static headspace (SHS)-GC-ECD [12,13] microextraction-GC-MS [14]. With respect to HAAs, their determinations by GC require a prior derivatization step due to their low volatility and high polarity.…”

Simultaneous quantification of trihalomethanes and haloacetic acids in cheese by on-line static headspace gas chromatography–mass spectrometry

“…Since there is significant exposure of humans to DBPs through foods and beverages, international organisations (FAO/WHO) have recommended the development of methods to determine DBPs in beverages and foods [27]. The formation of THMs during the preparation of beverages and some solid foods has been studied, the highest THM level being found in tea (chloroform from 3 to 67 g/L) [28,29]. Different methodologies have been used for the determination of THMs in beverages and foods, the most frequent being EPA methods based on LLE [30,31] or P&T, [32][33][34] and GC.…”

“…Different methodologies have been used for the determination of THMs in beverages and foods, the most frequent being EPA methods based on LLE [30,31] or P&T, [32][33][34] and GC. Other methods include SHS-GC-ECD [28,29] and SPME-GC-MS [35,36]. In these studies, chloroform (trichloromethane, TCM) and bromodichloromethane (BDCM) are the species found in foods at concentrations of 5-110 g/kg or 5-9 g/kg for TCM and BDCM, respectively, in some margarine, butter and sandwich cookies (40-70 positive samples out of a total of 234 foods) [32] or at a total THM concentration of undetected -60 g/L in beverages [31].…”