Centrifugation supernatant

Starch (20 mg, dry basis) in water (10 mL) is heated at certain temperatures in sealed tubes for 30 minutes. The tubes are then cooled to room temperature and centrifuged. Supernatant is withdrawn and its amylose content is determined according to the method of Williams et al. (1970). The value of amylose leaching reflects the association of amylose, and interactions between amylose and amylopectin in the starch. 

The determination of OXO in Japanese oyster was realized using reversed-phase HPLC. Samples were extracted with LLE and SPE recoveries were 88.3% (193). Oyster samples were homogenized with a phosphate buffer adjusted to pH 7. After centrifugation, supernatants were concentrated using an SPE C-18 cartridge. Before use, the cartridge was activated with MeOH and phosphate buffer. After the sample had been passed, the cartridge was flushed with water and the analytes were eluted with MeOH-orthophosphoric acid (9 1). The eluate was evaporated, and the residues were dissolved in the mobile phase. The method developed was validated and the study of OXO stability was performed. The limits of detection and determination were 10 and 40 ng/ml, respectively. 

Extraction (adapted from Bushway 1986 (369)) freeze-dried sample powder stirred in THF-H20-ACN. Extract centrifuged, supernatant collected and concentrated in a rotary evaporator, with added HC1, suspension centrifuged and pH adjusted with NH4OH to pH 10-11. Water bath at 70°C, 30 min. The precipitate collected and boiled in MeOH. Hot suspension filtered and evaporated. ACN-H20 added. 

Plasma plasma sample added with 300 fA ACN then vortexed and centrifuged. Supernatant was then concentrated down using sample concentrator, then added with 5 fA of 10 g/ml i.s. and 10 fA TFA to form precipitation and centrifuged. The resultant supernatant was then injected Urine similar with the plasma... 

Sample sample was acidified with 0.5 M sulfuric acid, vortexed and preserved at -20 °C. Sample was then added with i.s. in MeOH and 1 ml ACN then vortexed and centrifuged. Supernatant was drawn and evaporated under nitrogen stream to 100 or 150 /il volume Rec n/a... 

In experiments in which sulfur-3 5-labeled sulfate was used, the supernatant solutions containing the plasma seromucoids were mixed with 1.0 ml. of 1% sodium sulfate and digested on a steam bath with 10 ml. of 20% HC1 for about 2 hours, a time sufficient to convert all ester sulfate to inorganic sulfate. After an excess of 5% barium chloride was added, precipitates were digested for another 20 or 30 minutes on a steam bath and centrifuged. Supernatant clear fluid was removed,... 

After incubation treatment, sample was vortexed and centrifuged. Supernatant was withdrawn and injected LC-MS detection ... 

Sample added with ACN and centrifuged. Supernatant was then evaporated at 40 °C under nitrogen and residue was dissolved in mobile phase... 

During sample preparation, the post-centrifugation supernatant liquor was discarded. This facilitates drying of the sample since it allowed a greater sludge solids to soditun sulphate ratio to be obtained. 

Matrix cell suspensions Sample prepimation Centrifuge supernatant. 

Centrifugation, supernatant acidified with 3% formic acid... 

Centrifugation, supernatant pH raised to 11, dried at 95°C, redissolved in H3PO4... 

Parameter Primary influent Primary effluent Primary sludge Secondary effluent Waste activated sludge Anaerobic digester feed Centrifuge supernatant Centrifuge sludge... 

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