This paper evaluates quenching agents for disinfectant removal as well as preservation options for the determination of aldehydes in drinking water samples. Specifically, the quenching agents sodium thiosulfate and sodium sulfite were evaluated in addition to ammonium chloride. Samples should be analyzed immediately. If this is not possible, it is recommended that the derivatization and extraction be completed within 48 h of collection. Other preservation measures are not discussed. When shipping samples over long distances the 48 h requirement becomes difficult to fulfill. Alternate preservation modes were explored. One option is the addition of mercuric chloride while sampling. Another strategy relies on the addition of the derivatizing agent directly after sampling thus starting the derivatization reaction immediately.