| 摘要 |
1,236,676. Determination of carbon dioxide in liquid samples. TECHNICON INSTRUMENTS CORP. 26 Feb., 1969 [27 Feb., 1968], No. 10306/69. Heading B1X. In an apparatus for the quantative analysis of a gaseous constituent e.g. CO 2 , a first stream of sample and acid segments spaced apart by intermediate segments of CO 2 -free air is drawn via pump tubes 18, 22 and 24 by peristaltic type pump 20 through mixer 40 where sample and acid segments are uniformly mixed and CO 2 liberated is entrained in the liquid segments, into a donar stream 42 which flows over one face of a gas permeable, liquid impermeable membrane 50. A second stream of CO 2 -sensitive colour reagent segments spaced apart by CO 2 -free air segments is drawn via pump tubes 28 and 26 by peristaltic pump 20 into line 54 and so into stream 82 which flows over the second face of membrane 50. Carbon dioxide gas entrained in the first stream iquid segments then diffuses through the membrane 50 into the second colour reagent stream segments and in doing so alters both the pH and optical density of this liquid. The latter may be measured by means of colorimeter 62, stream 82 being drawn through the colorimeter by means of pump line 30 connected to peristaltic pump 20. Pinch bars 20a and 20b serve to introduce the segments of CO 2 - free air into the two liquid streams respectively being operated by periodical release of air from lines 24 and 26. The colour reagent may be a dilute solution of cresol red buffered to pH 9.2 with tris-methane and ammonium hydroxide. |
