Disposable pipets

Centrifuging the screw-cap vial can easily break emulsions, which often form during extraction. The vial will survive up to 6000 g if rubber stoppers are inserted into the centrifuge cup to provide a flat base for the vials. The required phase (usually the top layer) can be easily removed with a pipet or, if it is to be discarded, it can be removed using a disposable pipet connected by tubing to a suction flask and vacuum line. 

Pipet tips Sorenson Multiflt Research Pipet Tips 5-200 and 100-1000 p-L Rainin Certified Disposable Pipet Tips 10 mL... 

Spread the mix by using a medicine dropper. Do not use disposable pipets The disposable pipets have extremely narrow openings at the end and they clog up easily. There exists a dipping method for preparing TLC slides, but since the usual solvents, methanol and chloroform (Caution Toxic ) do not activate the binder, the powder falls off the plate. Because the layers formed by this process are very thin, they are very fragile. 

Use a disposable pipet to load your sample onto the column. The sample should go through the sand and become stuck on the adsorbant. 

Again, with a disposable pipet, carefully add clean eluent until you re sure all the sample is stuck on the adsorbant, and none of the sand. 

Get a disposable pipet and a little rubber bulb and construct a narrow medicine dropper. Use this to transfer your sample to the NMR tube. Don t fill it much higher than about 3-4 cm. Without any solvent, this is called, of course, a neat sample. 

The sample to be analyzed by chromatography should be applied to the top of the column in a concentrated form. If the sample is solid, it is dissolved in a minimum amount of solvent if already in solution, it may be concentrated by ultrafiltration as described in Chapter 2. After the sample is loaded onto the column with a graduated or disposable pipet, it is allowed to percolate into the adsorbent. A few milliliters of solvent are then carefully added to wash the sample into the column material. The column is then filled with eluting solvent. 

If the electrode response is sluggish, first check/replace the membrane since most 02 electrode problems are due to dirty or leaky membranes. Remove the cell plug and rinse the cell thoroughly with distilled water using a plastic disposable pipet to avoid the risk of damage to the membrane. 

Using a wash bottle makes it possible to wash down the condenser on all sides while keeping the volume of water used low the next best choice is to use a disposable pipet. Try not to use a beaker it lacks the control needed to get a good wash down and uses too much water. 

Using a disposable pipet, place 1 to 50 pi of the trans-free reference fat on the ATR horizontal surface, making sure that the surface of the ZnSe or diamond crystal is completely covered. 

Melt calibration standards (from step 1) in a water bath if necessary. Using a disposable pipet, place each standard on the ATR horizontal surface making sure that the surface of the ZnSe or diamond crytal is completely covered, collect a 128-scan single-beam FTIR spectrum (Fig. D1.7.1B) at 4 cm"1 resolution, and save it. Repeat step 5 after each measurement. 

Dosing solutions were mixed on a Fisher Rotorak for 45 min. Difficulty was encountered in weighing and preparing the technical grade dicofol. Whereas chlorobenzilate was a viscous material, dicofol was almost a wax. It was necessary to warm a small amount of the latter material in an aluminum weighing dish until it flowed. The liquid was taken up with a disposable pipet and quickly transferred to a tared volumetric flask on a balance. The effect of the heat (if any) on the material was not known. 

General Rules of Solubility as listed in Chapter 8 0.1 M solutions of the following compounds (these are the unknown solutions) Ag(N03) (silver nitrate), Ca(N03)2 (calcium nitrate), Cu(N03)2 (copper nitrate), NaOH (sodium hydroxide), KC1 (potassium chloride), Na2SC>4 (sodium sulfate), Nal (sodium iodide), and Na3PC>4 (sodium phosphate) eight small test tubes eight small disposable pipets pH paper one flame test wire in a cork glass plates a Bunsen burner and 3M HC1 (hydrochloric acid). 

Gentry dislodge the cells by a cell scraper, and disperse by gently pipeting up and down several times with a 5-mL plastic disposable pipet. 

Add equal volumes of 1.2% agar at 55°C and 2X alpha medium at 37°C and allow to equilibrate to 37°C for at least 10 min. Use plastic disposable pipets for all manipulations involving agar (see Note 2). 

Transfer the remaining hexane extract quantitatively with a disposable pipet into a 5-ml. volumetric flask. Bring this solution to volume... 

The solution is transferred with a disposable pipet to a 200-mL conical beaker, aided by a few drops of water. The beaker is placed in a nitrogen tilled desiccator. The desiccator lid is fltted with two glass tubes in a two-hole stopper. The nitrogen inlet tube extends to the bottom of the desiccator. The outlet tube is flush with the bottom of the stopper. After purging the desiccator with nitrogen for 15 min, the flow is reduced to one bubble every 2 sec from an oil bubbler. The desiccator is left at room temperature for 1 to 4 weeks. 

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