Disposable extraction columns

Octadecyl (Cig) SPE disposable extraction column, 2.8-mL capacity, 500-mg sorbent weight... 

Silica SPE disposable extraction column Sea sand, washed Volumetric flask, 100-mL Disposable culture mbes, 100 x 13-mm i.d. 

Use of disposable extraction columns (in a multitude of column sizes)... 

Aspec is designed to receive up to 108 samples. The system is compatible with most standard disposable extraction columns. Analytichem Bond-Elut Baker SPE, Supelco Supelclean, Alltech Extract Clean, etc. There is a choice of more than 20 different stationary phases. 

Implementing SPE in flow analysis without mini-columns is also feasible. To this end, other materials, e.g., commercially available ion-exchange or chelating extraction disks [231], disposable extracting cartridges [232], polymer-composite membranes [233] and monolithic columns [212], have been used. Analytical procedures exploiting addition, transport and disposal of the solid particles, analyte sorption/ elution in flow reversal, and the use of fluidised beads have also been proposed, as highlighted at the end of this section. 

Vitamin D has been analyzed in different food samples, including NIST 1849 (infant/adult nutritional formula), ready-to-eat cereal, bread, mushrooms, eggs, yogurt, cheese, fish, butter, milk (RTE infant formula), and premix (mixture of vitamins). After saponification with ethanol and potassium hydroxide, and sequential liquid-liquid extraction steps using ethanol, water, and n-heptane, the food samples were eluted through a disposable SPE silica gel column. The extracted samples were assayed using a methanol and ammonium formate gradient on a UPLC-MS/MS system equipped with an HSS Cjg UPLC (100 x 2.1 mm i.d., 1.8 pm particle size) column at 0.4 mL/min flow rate. The injection volume was 20 pL [92],... 

The extract is vacuum-distilled ia the solvent recovery column, which is operated at low bottom temperatures to minimise the formation of polymer and dimer and is designed to provide acryUc acid-free overheads for recycle as the extraction solvent. A small aqueous phase in the overheads is mixed with the raffinate from the extraction step. This aqueous material is stripped before disposal both to recover extraction solvent values and minimise waste organic disposal loads. 

Quantitatively transfer the hydrolysis reaction solution to a 50-mL glass culture tube with a screw-cap by rinsing witli 3x5 mL of deionized water followed by 5 mL of 30% (v/v) sulfuric acid and one additional 5 mL of deionized water. Rinse the Teflon culture tube with acetone and transfer to the glass culture tube. Extract the acidic aqueous phase (pH 1) with 3 x 2.5 mL of toluene. Pass each upper toluene phase through approximately 3 g of anhydrous sodium sulfate contained in a 6-mL disposable filtration cartridge into a 10-mL volumetric flask. Adjust the volume of the solution to 10 mL with toluene. Condition a 3-mL diolsilane bonded silica gel SPE cartridge with two column volumes of toluene. Load a 5-mL aliquot of toluene solution and collect the eluate in a 125-mL round-bottom flask. Elute the column with an additional 50 mL of toluene (use the 75-mL reservoirs) and collect the eluate in the same round-bottom flask. Concentrate the toluene extract to approximately 3.0 mL at 40 °C under weak reduced pressure with a rotary evaporator. 

Extract buprofezin and BF12 from the acidic aqueous phase with 25 mL of dichloromethane twice. Dry the extracts by passing them through anhydrous sodium sulfate held in a disposable filtration column and collect in a 125-mL round-bottom flask. 

Pankey et al.21 described a rapid, reliable, and specific enzyme multiplied immunoassay technique (EMIT ) for amitriptyline, nortriptyline, imipramine, and desipramine in sera. To overcome crossreactivity, solid phase extraction was included in sample pretreatment. Disposable 1 mL columns packed with covalently labeled silica gel were conditioned with HPLC-grade methanol (1 mL) and then with de-ionized or distilled water (1 mL). Serum (calibrator, control, or patient sample, 500 L) was applied onto the column, eluted to waste, washed with 900 /uL of wash solution containing acetonitrile (236.1 g/L) and ion-pairing reagent in acetate buffer, pH 4.2, washed with 500 fiL of mobile phase solution containing acetonitrile (393.5 g/L) in methanolic phosphate buffer, pH 7.0,... 

The Gilson Aspec automatic sample preparation system is a fully automated system for solid-phase extraction on disposable columns and online HPLC analysis. The Aspec system offers total automation and total control of the entire sample preparation process including clean-up and concentration. In addition, Aspec can automatically inject prepared samples into on-line HPLC systems. 

Methods have been described for determining chlorinated aliphatic hydrocarbons in soil and chemical waste disposal site samples. The latter method involves a simple hexane extraction and temperature programmed gas chromatographic analysis using electron capture detection and high resolution glass capillary columns. Combined gas chromatography-mass spectrometry was used to confirm the presence of the chlorocarbons in the samples [4],... 

Water/SPM Collect water samples on disposable octyl-bonded silica solid-phase extraction columns dry elute with hexane/ether SPM collected by continuous flow centrifugation extract with acetone/water/benzene GC/ECD GC/MS O.lpg/L (water) 0.1 mg/kg (suspended particulate) 83 (water) 82 (suspended particulate) Ritsema et al. 1989... 

Liquid chromatographic clean up [441,443,450] has been used either in normal phase flow using alumina, silica, or florisil [22,189,403,481,484] or with reverse-phase (RP) columns [409,452,480]. In most cases these techniques are well established and are used in an off-line mode, primarily to remove the bulk of co-extracted materials prior to a more refined clean-up prior to the final determination. These columns may be prepared in the laboratory [22,403 -405] or commercial solid phase extraction (SPE) cartridges can be used [409,452, 463,470,485,486]. In both cases, the normal phase cartridges and column materials are disposable since many of the polar co-extractants bind firmly to the substrate surface and are difficult to remove. This has been overcome to some... 

A pilot plant, containing two pulsed columns, one for extraction and one for stripping, and batchwise evaporation was in operation in Sweden during 1981. Pilot plant operations have also been performed in Holland (Fig. 14.6) and Germany. The experience from these tests shows that the process concept is technically practicable and well proven. The economics of the process, however, are strongly dependent on the cost for disposal of spent pickling liquors. 

The expense of the columns can be offset against savings in solvent purchase and disposal. Liquid/liquid extraction... 

Liquid-liquid partitioning cleanup on a hydrophilic matrix has also been employed for purification of the primary sample extract. This procedure was only applied in the determination of fenbendazole and four metabolites in plasma and liver using a Chem Elut disposable column to partition an alkalinized aqueous sample extract into dichloromethane (371). In a few instances, further cleanup can also be achieved by submitting an organic extract to freezing at 20 C, a procedure that can precipitate dissolved matrix components (359, 366, 367). 

Cleanup by solid-phase extraction has also been widely employed since it is a simple, fairly inexpensive, and easy-to-perform procedure for purification of the crude extract. The use of disposable solid-phase extraction columns is currently part of most, if not all, modern analytical methods for the determination of anthelminthics in biological matrices at residue levels. Both normal-phase columns based on silica (333-335, 340, 367, 372), alumina (346, 373-375), or aminopropyl (339, 365, 370) materials, and reversed-phase columns based on Ci8 (319, 323, 324, 328, 344, 346, 347, 349-351, 357-359, 364, 367) and cyclohexyl (329, 332, 360) sorbents have been described in analytical applications. 

The 3 ml of new mixture is now passed on a disposable solid phase extraction column in order to separate the cyclosporins retained upon the sorbent. Following the rinsing and drying of the column, the cyclosporins are eluted with 1.5 ml of acetonitrile and are then concentrated to 200 pi following evaporation of solvent. A fraction of this final solution is injected into the chromatograph. 

---