Shaking extraction

In liquid-solid extraction (LSE) the analyte is extracted from the solid by a liquid, which is separated by filtration. Numerous extraction processes, representing various types and levels of energy, have been described steam distillation, simultaneous steam distillation-solvent extraction (SDE), passive hot solvent extraction, forced-flow leaching, (automated) Soxh-let extraction, shake-flask method, mechanically agitated reflux extraction, ultrasound-assisted extraction, y -ray-assisted extraction, microwave-assisted extraction (MAE), microwave-enhanced extraction (Soxwave ), microwave-assisted process (MAP ), gas-phase MAE, enhanced fluidity extraction, hot (subcritical) water extraction, supercritical fluid extraction (SFE), supercritical assisted liquid extraction, pressurised hot water extraction, enhanced solvent extraction (ESE ), solu-tion/precipitation, etc. The most successful systems are described in Sections 3.3.3-3.4.6. Other, less frequently... 

Test 1. Mix a quantity containing 40 mg of miconazole nitrate with 20 mL of a mixture of 1 volume of 1 M sulfuric acid and 4 volumes of methanol and shake with two 50 mL quantities of hexane, discarding the organic layers. Make the aqueous phase alkaline with 2 M ammonia and extract with two 40 mL quantities of chloroform. Combine the chloroform extracts, shake with 5 g of anhydrous sodium sulfate, filter, and dilute the filtrate to 100 mL with chloroform. Evaporate 50 mL to dryness and dissolve the residue in 50 mL of a mixture of 1 volume of 0.1 M hydrochloric acid and 9 volumes of methanol. The light absorption of the resulting solution, Appendix II B, in the range 230-350 nm exhibits maxima at 264, 272, and 282 nm. 

Soil (DPTA extractable) Shake soil with 0.005 MDPTA extraction solution for 2 hours AAS No data No data Baker and Amacher 1982... 

Powder the 25 G sample and place it into a glass mason jar that has a screw top (make sure the seal on the jar top is not soluble in the solvent). Add at least 125 ml (1/2 cup) of solvent. Screw on the top. Shake well for 2 minutes. Let sit for a minimum of 24 hours (several days might yield a more complete extraction). Shake periodically (at least 5 or 6 times over the course of the extraction period). Then pour the entire contents of the jar though a fine mesh wire strainer (a tea strainer will do). Save all the solvent. With the back of a spoon squeeze the stuff in the strainer dry. Save the solvent that you squeeze out. Re-extract the filtered leaf material in an addition 125 ml fresh solvent. As... 

In addition to the above, there might be other less common causes for IS response variations. For example, due to mixed usage of rubber-lined caps and FIFE (polytetrafluoroethylene)-lined caps during the liquid-liquid extraction shaking (mixing) step, randomly low IS responses were observed for extracted samples, i.e.,... 

Bromides and iodides interfere because of the liberated halogen the test is not trustworthy in the presence of chromates, sulphites, thiosulphates, iodates, cyanides, thiocyanates, hexacyanoferrate(II) and (III) ions. All of these anions may be removed by adding excess of nitrate-free Ag2S04 to an aqueous solution (or sodium carbonate extract), shaking vigorously for 3-4 minutes, and filtering the insoluble silver salts, etc. 

Dilution Solid-liquid extraction (shake filter)... 

Note, To separate lead from any bismuth present in the extract, shake the CCI4 extract with -0.01 M HCl (pH 3.0-3.5) Pb passes into the aqueous phase. Adjust the aqueous solution with ammonia to pH -8, add some KCN solution, and extract the lead with dithizone as stated above. 

Methods Extractant composition Soil extractant Shaking time... 

Weigh accurately 10 g of soil sample in a 100 ml conical flask and add 20 ml of DTPA extractant, shake for 2 hours. 

Extraction Shaking, ultrasonication, Soxhlet, liquid-liquid partitioning, solid-phase extraction To extract analytes from sample matrix into solution... 

Centrifugation, separation of organic phase, on-batch clean-up by addition of 100 mg florisil per mL extract, shaking 2 min, and filtration. An ahquot of 2 mL concentrated to 0.2 mL... 

Add 10 ml of dilute nitric acid to the chloroform extract. Shake vigorously for 1 minute and reject the chloroform layer as completely as possible. Add 5 ml chloroform to the aqueous solution, shake and again reject the chloroform layer. 

NOTE. The volumes of liquid used in the extraction are measured using calibrated Pasteur pipets. For each extraction, shake the vial, vent it carefully, and allow the layers to separate. The transfers are made using Pasteur filter pipets. 

When the extraction is complete, add 1 g. of acid-washed Norit per 60 ml. of extract. Shake vigorously and filter, preferably through a Whatman No. 12 folded filter paper. 

Add 10 ml of N sulphuric acid to the combined extracts, shake for five seconds, and allow the layers to separate. Run the chloroform layer into a 50-ml conical flask, wash the sulphuric acid layer with two small portions of chloroform, without mixing, and add the washings to the chloroform solution in the flask. During this operation care must be taken not to allow any of the aqueous layer to enter the tap of the funnel. 

For assay by base extraction shake a quantity of powdered tablets containing about 0 1 g of morphine sulphate in a separator with 25 ml of water and 5 ml of N sodium hydroxide. Continue by the Nicholls extraction method given above, after addition of 1 g of ammonium sulphate and titrate the residue of morphine. 

Extraction Shake 10-15 g sample with solvent and salts... 

Liquid extraction Shake with pentane, 10 min Concentrate organic phase to 400 pL... 

---