| 摘要 |
1,146,910. Determining 1 -phenyl-3-pyrazolidone photo-electrically. RUMANIA STATE BOARD FOR CULTURE and ART. July 8, 1966 [July 13, 1965], No. 30676/66. Heading G1A. 1-phenyl-3-pyrazolidone in a photographic developing solution is determined by diluting the solution with a buffer solution and measuring the blackening effect produced on uniformally exposed film by the diluted solution. Preferably the blackening is measured whilst the film is in the developing solution. The developing solution is diluted to a 1 -phenyl-3-pyrazolidone concentration in the range 0À003 to 0À05 g/1 by the addition of a buffer solution comprising 200 g/1 crystallized sodium sulphite; 2 g/1 borax; 3 g/1 boric acid and 1 g/1 potassium bromide. The diluted solution is introduced into a tank 3 having an overflow level regulator 10 and means for supporting a film 2 which has been exposed on half its width. The film blackening is measured by comparing the outputs of photo-cells 7 one of which receives light through the film and the other directly from a source 8. Pushing the handle 20 brings the film 2 into the solution and at the same time starts a clock 8 so that the blackening can be read off meter 19 after a predetermined time, and used to determine the concentration of 1-phenyl-3- pyrazolidone from a calibration curve produced using known concentrations. Diaphragms 6 are provided for setting the zero of meter 19. |
