Somogyi’s copper reagent

Somogyi s Copper Reagent Dissolve 14.0 g of anhydrous dibasic sodium phosphate and 20.0 g of potassium sodium tartrate tetrahydrate into 250 mL of water. Add 60.0 g of 1 M sodium hydroxide solution. Dissolve 4.0 g of cupric sulfate pentahydrate into 25 mL of water. Add this solution to the tartrate solution. Add 90.0 g of anhydrous sodium sulfate while stirring. Dilute the final solution to 500 mL. 

Procedure Transfer 1.0-mL aliquots of Pullulan Substrate to separate 15- x 150-mm test tubes. Insert a one-hole stopper in each tube, and equilibrate for 15 min in a 40° 0.1° water bath. At time equals zero and at 30-s intervals, add 1 mL of the respective samples, and mix. Exactly 30.0 min after addition of the samples, add 2.0 mL of Somogyi s Copper Reagent to each tube to terminate the reaction. Mix thoroughly, and allow the tubes to come to room temperature. To obtain sample blanks, add the Somogyi s Copper Reagent to the sample before adding the substrate. 

Prepare a standard curve by adding 2.0 mL of each glucose standard and 2.0 mL of Somogyi s Copper Reagent to a test tube, and mix. The blanks and Glucose Standards should not be incubated at 40°. 

Loosely stopper samples, blanks, and Glucose Standards containing Somogyi s Copper Reagent, and place them in a vigorously boiling water bath for exactly 25.0 min. Cool in an ice-water bath for approximately 1 min. 

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