Disk extraction

Extraction of water using C g extraction disks (LSE) elution using ethyl acetate and methylene chloride volume reduction... 

Supercritical fluid extraction (SFE) is generally used for the extraction of selected analytes from solid sample matrices, but applications have been reported for aqueous samples. In one study, recoveries of 87-100% were obtained for simazine, propazine, and trietazine at the 0.05 ug mL concentration level using methanol-modified CO2 (10%, v/v) to extract the analytes, previously preconcentrated on a C-18 Empore extraction disk. The analysis was performed using LC/UV detection. Freeze-dried water samples were subjected to SFE for atrazine and simazine, and the optimum recoveries were obtained using the mildest conditions studied (50 °C, 20 MPa, and 30 mL of CO2). In some cases when using LEE and LC analysis, co-extracted humic substances created interference for the more polar metabolites when compared with SFE for the preparation of the same water sample. ... 

For water, bispyribac is extracted with a Cig solid-phase extraction disk. After methylation, bispyribac-methyl is determined by gas chromatography. 

Silica gel mini column, Sep-Pak Plus Silica To set up, attach a Sep-Pak Plus Silica column to a vacuum manifold and rinse with 10 mL of ethyl acetate Empore Cig extraction disks (3M) To set up, attach Cig extraction disks to a two-piece Alter funnel and load 30 g of Filter Aid 400 on its surface. Wash the Alter with 20 mL of acetoniAile and 20 mL of 0.01 M acetate buffer (pH 4) in that order Filter Aid 400 (3M)... 

To 100 mL of the water sample add 20 mL of 0.2 M acetate buffer (pH 4) to acidify the mixture to pH 4. Filter the solution through a Cig extraction disk with suction and rinse the disk with 50 mL of acetonitrile-water (1 19, v/v). Discard the eluate. Collect the bispyribac in a 500-mL round-bottom flask with 100 mL of acetonitrile. Evaporate the eluate to dryness under reduced pressure. Then the residue is processed as described below. 

The use of SPE disks represents a relatively new SPE approach for the rapid and efficient isolation of pesticides from aqueous samples. Empore extraction disks have approximately 10 times the cross-sectional area of conventional SPE cartridges with comparable solvent mass (500 mg). The dense packing and uniform particle... 

In summary, the development of materials for the extraction of pesticides from water samples has progressed from simple liquid-liquid extraction for the principal active compound to sophisticated SPE media capable of exclusively trapping the target pesticide and metabolites selectively. The development of alkyl bonded phase silica cartridges and extraction disks combined with on-line extraction techniques is currently the principal means used for the extraction and trace enrichment of pesticides and metabolites from water. 

Filter IL of water sample through a filter paper. Place an Empore extraction disk in a Millipore extraction funnel. Rinse the disk with 10 mL of ethyl acetate, dichloromethane, and acetonitrile, successively. Dry the disk under vacuum and then rinse the disk with 10 mL of methanol and 20 mL of deionized water by vacuum filtration. Pass the prefiltered sample through the disk and elute alanycarb with two portions of 10 mL of acetonitrile. Transfer the eluates through anhydrous sodium sulfate into a 50-mL flask. Remove acetonitrile by rotary evaporation. Dissolve the residue in 1 mL of acetonitrile. 

Kraut-Vass A, Thoma J. 1991. Performance of an extraction disk in synthetic organic chemical analysis using gas chromatograph-mass spectrometry. J Chromatog 538 233-240. 

TOOOl 3M Company, 3M Empore Extraction Disk T0124 BioTrol, Inc., Soil Washing Technology T0161 Chemical Oxidation—General... 

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