Glutaraldehyde bath, aqueous

Cyano-6-phenyloxazolopiperidine. A 2-L, round-bottomed flask is charged with 10 g (0.073 mol) of (-)-phenylglycinol (Note 1) and 40 g of citric acid in 1 L of distilled water. The mixture is stirred magnetically until complete dissolution is achieved and is cooled to 0-5°C (ice-water bath). The flask is equipped with a dropping funnel and 45 mL of an aqueous 24% glutaraldehyde solution (0.11 mol) is added dropwise over 20 min and the resultant cloudy solution is stirred for an... 

The first step in preparing a sensor is to dissolve 100 mg of PVOH/indicator conjugate in 2.0 mL of water. Five minutes in a water bath at 30°C is required to get the PVOH to dissolve. After cooling to room temperature, 0.5 mL of PVOH/indicator solution is combined with 0.050 mLs each of 2% aqueous glutaraldehyde and 4 M HCl. This mixture can be manipulated as a liquid for about five, minutes until sufficient crnsslinking takes place to cause the solution to gel. During this interval a micropipet is used to precisely transfer 3 microliters to the common end of the bifurcated fiber optic bundle so that the gel forms in situ. 

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