Sains Ma1aysiana 28: 119-126 (1999) Sains Fizis dan Gunaan/
Physical and Applied Science
The Use of Solid Phase Microextraction Technique for the
Extraction of Trihalomethanes in Drinking Water
Md. Pauzi Abdullah & Aiman M. Bobaker
Jabatan Kimia, Fakulti Sains Fizis dan Gunaan
Universiti Kebangsaan Malaysia
43600 UKM Bangi Selangor D.E. Malaysia
ABSTRACT
Solid phase micro-extraction technique is a fast, sensitive, inexpensive, portable and solvent free method for extracting organic compounds from aqueous samples. This technique involves exposing a fused silica fibre that has been coated with a stationary phase to an aqueous solution containing organic contaminants. The analytes partition into the stationary phase until an equilibrium has been reached, after which the fibre is removed from the solution and the analytes are thermally desorbed into the injector of a gas chromatograph. Optimization work were carried out for the time of absorption and desorption, and the equilibrium temperatures for the extraction of trihalomethanes in drinking water samples. Almost 100% recovery was achieved within three minutes of equilibration between 25 to 30°C with desorption time of two minutes. The samples of drinking water supplies were analyzed against calibrated standard solutions in deionized water. With 20.0 ml water sample, the method's detection limit MDL of 0.01 ppb was achieved for CHCl3 and CHBrCI2. For CHBr2Cl and CHBr3 the MDL were 0.04 and 0.06 ppb, respectively.
ABSTRAK
Teknik pengekstrakan mikro fasa pepejal ialah satu teknik pengekstrakan sebatian organik yang cepat, peka, murah dan bebas pelarut. Teknik ini melibatkan pencelupan gentian silika terlakur yang dilapisi dengan suatu fasa pegun ke dalam larutan yang mengandungi pencemar organik. Analit organik akan terjerap kepada gentian sehingga mencapai keseimbangan. Gentian yang mengandungi organik terjerap dikeluarkan daripada larutan dan kemudiannya dinyahjerap di dalam penyuntik alat kromatografi gas. Teknik ini telah dioptimumkan dari segi masa jerapan, masa nyahjerapan dan suhu keseimbangan. Hampir 100% pemulihan dicapai dengan masa keseimbangan selama 3 minit pada suhu antara 25°C ke 30°C dan dengan masa nyahjerap selama 2 minit. Analisis ke atas beberapa sampel air minum telah dilakukan menggunakan teknik ini. Bagi isipadu sampel sebanyak 20.0 ml, had pengesanan kaedah serendah 0.01 ppb telah dicapai bagi komponen CHCI3 dan CHBrCI2. Bagi CHBr2Cl dan CHBr3, had pengesanan kaedah masing-masingnya ialah 0.04 dan 0.06 ppb.
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