Analysis of Haloacetic Acids

Gabryelski W, Wu F, Froese KL (2003) Comparison of high-field asymmetric waveform ion mobility spectrometry with GC methods in analysis of haloacetic acids in drinking water. Anal Chem 75(10) 2478-2486... 

Sarri6n, M. N., Santos, F. J., and Galceran, M. T., Solid-phase microextraction coupled with gas chromatography-ion trap mass spectrometry for the analysis of haloacetic acids in water, J. Chromatogr. A, 859, 159-171, 1999. 

The advantages of IC-MS such as sensitivity and selectivity are noticeable in the analysis of drinking water (e.g., for the determination of perchlorate, the analysis of haloacetic acids or of disinfection by-products). Other fields of >pli-cation are clinical and biochemical research (determination of organic acids, amines, or sugars),pharmaceutical industry (peak identification and purity tests), petrochemical industry (determination of indicator substances), food industry, electroplating industry, analysis of hazardous substances, and environmental analysis. " ... 

Figure 3.71 Analysis of haloacetic acids on lonPac AS24 using MS/MS detection. Separator column lonPac AS24 column dimensions 250 mm x 2 mm i.d. column temperature 15°C eluent KOH (EG) gradient 7 mmol/L in 0 to 18 min, 7-18 mmol/L in 18 to 36.5 min,...

Figure 10.39 Trace analysis of haloacetic acids standards with ICP-MS as an element-specific detection system. Separator column lonPac AS16 column dimensions 250mmx4mm i.d. eluent NaOH gradient 20mmol/L from 0 to 3 min, then step to 100 mmol/L in 0.1 min, and isocratic at 100 mmol/L for 9 min flow rate 1 mL/min detection ICP-MS ...

Disinfectants are usually only monitored to ensure that disinfection has taken place. Certain disinfectants, such as chlorine, are sometimes monitored at the tap or in the distribution system, as a measure of the quality in distribution. A wide range of potential by-products of disinfection may be formed in treatment, particularly if natural organic matter is present at high concentrations. The most commonly monitored by-products are the trihalomethanes (THMs) formed through chlorination THMs are normally considered to be an adequate marker of the total disinfection by-products from chlorination. Some countries also monitor haloacetic acids, but these are difficult and expensive to analyse because of their high polarity. Bromate is sometimes measured when ozone is used, but its formation relates to bromide concentrations in the raw water and the conditions of ozonation. Analysis can be extremely difficult and monitoring is not usually considered except where standards have been set or on an infrequent basis. 

As a result of the disinfection of drinking water by means of ozone, chlorine dioxide, chloramine, and chlorine, a variety of disinfection byproducts may occur in drinking water, including oxyhalides, haloacetic acids, and halogenated AEO and APEO metabolites (Ch. 8.4.2). The LC-MS analysis of disinfection byproducts in drinking water was recently reviewed by Zwiener and Richardson [65]. 

The haloacetic acids (HAA) are comprised of mono-, di- and trichloroacetic acid, mono-, di-, and tribromoacetic acid, and bromo-chloroacetic acid, bromo-dichloroacetic acid, and dibromo-chloroacetic acid. Toxicological studies showed that these compounds have carcinogenic properties and may have adverse reproductive consequences. HAA have no strong chromophore for sensitive UV detection electrochemical detection has been described. Analysis by GC-MS requires derivatization. Due to their relatively low molecular mass, the LC-MS analysis can be hindered by low-mass background interferences. 

The thermodynamic data for complexation of trivalent lanthanide and actinide cations with halate and haloacetate anions are reported. These data are analyzed for estimates of the relative amounts of inner (contact) and outer (solvent separated) sphere complexation. The halate data reflected increasing inner sphere character as the halic acid pKa increased. Use of a Born-type equation with the haloacetic acid pKa values allowed estimation of the effective charge of the carboxylate group. These values were, in turn, used to calculate the inner sphere stability constants with the M(III) ions. This analysis indicates increasing the inner sphere complexation with increasing pKa but relatively constant outer sphere complexation. 

In the disinfection process of drinking water, besides other chlorinated compounds, halogenated carboxylic acids arise. For quality control of drinking water the determination of these contaminants was established using LC-MS with a preference for ESI (cf 15.3.3.2 ESI, haloacetic acids). An application of APCI-MS for haloacetic acid analysis was reported after CE separation in a non-aqueous medium [303]. 

In water, GC-MS is coupled to purge and trap or headspace sample preparation for the analysis of VOCs like BTEX and MTBE. Another important group of volatile analytes in water are DBFs. Attention has been directed to volatile chlorinated compounds such as trihalomethanes (THMs), as well as other semivolatile compounds such as haloacetic acids (HAAs), haloacetonitriles, haloketones, and ha-loaldehydes. The methods used to determine these compounds include GC-EI-LRMS, where a after derivatization step is necessary due to the low volatility and high polarity of these analytes. Using this technique, limits of detection were in the microgram per liter range. 

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