Array capillary in-tube solid-phase microextraction: a rapid preparation technique for water samples.
A rapid sample preparation technique, namely array capillary in-tube solid-phase microextraction (ACIT-SPME) for direct extraction of organic pollutants from water samples, was developed and evaluated. The ACIT-SPME cartridge consisted of a bundle of glass capillary tubes of 0.5 mm I.D. × 30mm contained inside a quartz liner of 4 mm I.D. The high ratio of cross-section area of channel-to-wall allowed water sample flow through the cartridge just under gravity. Both the internal/external surfaces of the array capillary tubing were coated with extraction phase of 2-5 μm in thickness, which provided large extraction surface area up to 30 cm² for a cartridge containing 19 glass capillaries. The large surface area and thin extraction phase improved greatly both the mass transfer process of extraction and the thermo desorption process, leading to fast extraction and fast desorption. The extracted analytes were thermally desorbed in a homemade thermal desorption unit (TDU), which was coupled to a gas chromatograph equipped with a flame ionization detector for analysis. By using polydimethylsiloxane (PDMS) as the extraction phase and polycyclic aromatic hydrocarbons (PAHs) as the model analytes, the performance of the ACIT-SPME cartridge was systematically investigated. The extraction time was 2 min for 350 mL of water sample, and detection limits were between 0.8 and 1.7 ng/L with deviation of 2.8-9.7% RSD. Relative recoveries of analytes for real water samples were between 65.0% and 116%. The extraction time can even be further shortened to 10s for 250 mL sample by applying vacuum at the outlet of the cartridge, with detection limits of 2.2-5.3 ng/L and deviation of 4.0-12% RSD.
Department of Instrumentation & Analytical Chemistry, Key Lab of Separation Science for Analytical Chemistry of CAS, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, No. 457 Zhongshan Road, Dalian 116023, China.
Xiaohui
X
Yan
Dapeng
D
Wu
Hong
H
Peng
Kun
K
Ding
Chunfeng
C
Duan
Yafeng
Y
Guan
D002849:Chromatography, Gas; D004129:Dimethylpolysiloxanes; D060766:Drinking Water / Q000737:chemistry; D004867:Equipment Design; D006112:Gravitation; D057230:Limit of Detection; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis / Q000302:isolation & purification*; D015203:Reproducibility of Results; D045483:Rivers / Q000737:chemistry; D052617:Solid Phase Microextraction / Q000295:instrumentation / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000302:isolation & purification*
D004129:Dimethylpolysiloxanes; D060766:Drinking Water; D011084:Polycyclic Aromatic Hydrocarbons; D014874:Water Pollutants, Chemical; C013830:baysilon