Development of an Analytical Procedure for the Determination of Trihalomethanes in Leafy Vegetable by Headspace-SPME Followed by GC-ECD Determination

Trihalomethanes in water samples: Recent update on pretreatment and detection methods

Trihalomethanes (THMs) are classified as volatile organic compounds, considered to be a disinfection by-product during water disinfection process. THMs have been shown to be cytotoxic, genotoxic and mutagenic, with a risk of cancer when they contact with people directly. To protect public health and monitor water quality, it is important to monitor and measure THMs in drinking water. Therefore, it is crucial to develop fast, accurate, highly sensitivity and green analysis methods of THMs in various complicated matrices. Here, this review presents an overall summary of the current state of the pretreatment and detection methods for THMs in various sample matrices since 2005. In addition to the traditionally used pretreatment methods for THMs (such as headspace extraction, microwave-assisted extraction, liquid-liquid extraction), the new-developed methods, including solid-phase extraction, QuEChERS and different microextraction methods, have been summarized. The detection methods include gas chromatography-based methods, sensors and several other approaches. Additionally, benefits and limitations of different techniques were also discussed and compared. This study is anticipated to offer fruitful insights into the further advancement and widespread applications of pretreatment and detection technologies for THMs as well as for related substances.

Disinfection by-products in baby lettuce irrigated with electrolysed water

BACKGROUND

Irrigation water disinfection reduces the microbial load but it might lead to the formation and accumulation of disinfection by-products (DBPs) in the crop. If DBPs are present in the irrigation water, they can accumulate in the crop, particularly after the regrowth, and be affected by the postharvest handling such as washing and storage. To evaluate the potential accumulation of DBPs, baby lettuce was grown using irrigation water treated with electrolysed water (EW) in a commercial greenhouse over three consecutive harvests and regrowths. The impact of postharvest practices such as washing and storage on DBP content was also assessed.

RESULTS

Use of EW caused the accumulation of chlorates in irrigation water (0.02-0.14 mg L-1 ), and in the fresh produce (0.05-0.10 mg kg-1 ). On the other hand, the disinfection treatment had minor impact regarding the presence of trihalomethanes (THMs) in water (0.3-8.7 μg L-1 max), and in baby lettuce (0.3-2.9 μg kg-1 max).

CONCLUSIONS

Disinfection of irrigation water with EW caused the accumulation of chlorates in the crop reaching levels higher than the current maximum residual limit established in the EU legislation for leafy greens. © 2017 Society of Chemical Industry.