Analysis of Hydrazine in Drinking Water by Isotope Dilution Gas Chromatography/Tandem Mass Spectrometry with Derivatization and Liquid−Liquid Extraction

Abstract

A new isotope dilution gas chromatography/chemical ionization/tandem mass spectrometric method was developed for the analysis of carcinogenic hydrazine in drinking water. The sample preparation was performed by using the optimized derivatization and multiple liquid-liquid extraction techniques. Using the direct aqueous-phase derivatization with acetone, hydrazine and isotopically labeled hydrazine-(15)N2 used as the surrogate standard formed acetone azine and acetone azine-(15)N2, respectively. These derivatives were then extracted with dichloromethane. Prior to analysis using methanol as the chemical ionization reagent gas, the extract was dried with anhydrous sodium sulfate, concentrated through evaporation, and then fortified with isotopically labeled N-nitrosodimethylamine-d6 used as the internal standard to quantify the extracted acetone azine-(15)N2. The extracted acetone azine was quantified against the extracted acetone azine-(15)N2. The isotope dilution standard calibration curve resulted in a linear regression correlation coefficient (R) of 0.999. The obtained method detection limit was 0.70 ng/L for hydrazine in reagent water samples, fortified at a concentration of 1.0 ng/L. For reagent water samples fortified at a concentration of 20.0 ng/L, the mean recoveries were 102% with a relative standard deviation of 13.7% for hydrazine and 106% with a relative standard deviation of 12.5% for hydrazine-(15)N2. Hydrazine at 0.5-2.6 ng/L was detected in 7 out of 13 chloraminated drinking water samples but was not detected in the rest of the chloraminated drinking water samples and the studied chlorinated drinking water sample.

Total organic iodine measurement: A new approach with UPLC/ESI-MS for off-line iodide separation/detection

“…The standard deviation of the seven analyses was calculated to be 1.2 mg/L as I. Accordingly, the method detection limit was 3.14 times of the standard deviation, which was 3.7 mg/L as I (3.14 is the student t value for the 99% confidence level with À1 degrees of freedom) (Davis and Li, 2008).…”

Simple and sensitive determination of hydrazine in drinking water by ultra-high-performance liquid chromatography–tandem mass spectrometry after derivatization with naphthalene-2,3-dialdehyde

“…By comparing hydrazine concentrations detected in the same drinking water plant, hydrazine was detected in higher concentrations in chlorinated drinking water than in raw drinking water. The presence of ammonia in the raw drinking water source may result in the formation of hydrazine, which can be produced from the reaction of monochloramine with ammonia [17][18][19].…”

“…Hydrazine can be produced by the reaction of monochloramine with ammonia under chloramination [17][18][19] but it is not known if it can also be formed with conventional chlorination techniques. Due to these toxicological effects and its potential formation in drinking water under conventional chlorination, analytical approaches capable of detecting trace levels of hydrazine are required.…”

“…Specifically, gas chromatography (GC) and high performance liquid chromatography (HPLC) are typically used for the determination of hydrazine in water. GC methods for hydrazine have been developed using electron capture detection [21], nitrogen-selective detection [22,23], flame-ionization detection [24], mass spectrometry (MS) [23,[25][26][27], and tandem mass spectrometry (MS/MS) [19,28]. HPLC methods have also been developed using diode array detection [20,[29][30][31] and fluorescence detection [32][33][34][35].…”

“…In GC, derivatization reagents, such as acetone [19], pentafluorobenzaldehyde [21,23], benzaldehyde [22], ethyl chloroformate [24], n-hexyl chloroformate [25], octafluoropentylchloroformate [26], ortho-phthalaldehyde (OPA) [27], and propyl chloroformate [28], have been used. However, these GC methods require additional extraction and concentration steps after derivatization.…”