On the value of Brücke's method for the removal of interfering substances from urine in testing for glucose / by Edgar Moore Green.

  • Edgar Moore Green
Date:
[1886]
Catalogue details

Licence: Public Domain Mark

Credit: On the value of Brücke's method for the removal of interfering substances from urine in testing for glucose / by Edgar Moore Green. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    IO After precipitation by plumbic tribasic acetate in one solution, containing 0.05 gram of glucose, 47.40 per cent, was recovered. In four solutions, each containing 0.25 gram, 65.60 per cent, was recovered. In three solutions, each containing 0.5 gram, 80.04 per cent, was recovered, and in two solutions, each containing 1.0 gram, 83.42 per cent, was recovered. In these ten solutions, then, the average amount recovered was 71.67 per cent. At the end of the process in two solutions, each containing 0.025 gram of glucose, 59.00 per cent, was recovered. In six solutions, each of which contained 0.05 gram of glucose, 40.84 per cent, was recovered. In six solutions, each of which contained 0.25 gram, 51.69 per cent, was recovered. In five solutions, each of which contained 0.5 gram of glucose, 49.13 per cent, and in two solutions, each containing 1.0 gram of glucose, 47.70 per cent, was recovered. When hydrogen sulphide is used to precipitate the lead, it is certain that no one step in the process can be said to be specially faulty. The loss occasioned by the precipitation by neutral plumbic, acetate (as seen by Table V) is greater than that caused by plumbic tribasic acetate, but neither of these losses is equal to that which takes place at later steps in the process. Moreover, the losses are not uniform, but very variable in different solutions. And in the experiments this variation was found to exist, even though the solutions were subjected to exactly the same conditions, and even when the corresponding precipitates, in each case, were washed the same number of times and with equal volumes of water. Hence, from any amount of glucose found after employing the process, it could not be determined how much had originally been present in the urine. The process certainly removes the interfering substances from the urine; but even for qualitative work, if no reaction for glucose could be obtained after making use of the process, it would be by no means certain that no glucose had been originally present in the urine. In completing this paper the writer desires to express his great indebtedness to Dr. John Marshall, Demonstrator of Chemistry in the Medical Department of the University of Pennsylvania, for his valuable suggestions in carrying on the work, and to whom any success attained in the experiments is largely due. Chemical Laboratory, Med. Dept., University of Pennsylvania.
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