Ion Chromatographic Determination of Haloacetates in Environmental Samples
Wang, F (2004) Ion Chromatographic Determination of Haloacetates in Environmental Samples. Research Master thesis, University of Tasmania.
A method is reported for the sensitive, simultaneous determination of mono-, di-, and trifluoroacetates
by ion chromatography. These species were separated using a Dionex AS17 anion-exchange column employed with a potassium hydroxide gradient (via a Dionex EG40 Eluent Generator) and suppressed conductivity detection. The fluoroacetates were successfully separated from a range of inorganic and organic species likely to be present in environmental samples, in a total analysis time of 35 min (including re-equilibration of the column). Detection limits for mono-, di- and trifluoroacetate were 21, 38 and 36 micrograms/L, respectively, determined using a signal to noise
ratio of 3, and were obtained using a sample injection volume of 50 microlitres. Precision was less than 0.83% relative standard deviation for replicate injections performed over a period of 30 days. The method was applied to the determination of MFA, DFA and TFA in river water, carrot baits, urine samples and different kinds of plant material including Bilobum, Calvcinum and Spinosum, and found the concentration range of mono-(MFA), di-(DFA), tri-fluoroacetate (TFA) to be 11-788, 3.5-17 and 0.22-1.2 ppm in wet weight plant samples respectively.
Further research was carried out using the Dionex equipment specified above.
A comparative study was made of the chromatographic behaviour of nine haloacetic
acids mono-(MFA), di-(DFA), tri-fluoroacetate (TFA); mono-(MCA), di-(DCA), trichloroacetate
(TCA) and mono-(MBA), di-(DBA), tri-bromoacetate (TBA). The techniques included anion-exchange chromatography with suppressed conductivity and
UV detection. All nine haloacetic acids were completely separated under the optimised
gradient elution conditions. Using selective detection methods or by pretreating samples
with a OnGuard II Ag cartridge, eliminated some interference. The procedure for the
simultaneous determination of the nine haloacetic acids was simple and fast. The method
detection limits for MFA, DFA, TFA, MCA, DCA, TCA, MBA, DBA, and TBA were
21, 40, 40, 48, 28, 86, 67, 55, and 160 ppb respectively, determined using a signal to
noise ratio of 3. Applications of these methods for the determination of haloacetic acids
in real soil samples are shown.
|Item Type:||Thesis (Research Master)|
|Keywords:||Haloacetates, Ion Chromatography|
|Deposited By:||utas eprints|
|Deposited On:||10 Aug 2006|
|Last Modified:||18 Jul 2008 19:41|
|ePrint Statistics:||View statistics for this ePrint|
Repository Staff Only: item control page