A new chemiluminescence system for determination of cobalt.
The chemiluminescence of the reaction of tartaric acid with hydrogen peroxide in the presence of Co(II) in alkaline buffer media has been examined. The maximum emission wavelength is 460 nm. The kinetic curve of the chemiluminescence system has been modelled with a computer, and the reaction conditions have been optimized. Foreign ions, such as Fe(II), Cr(III) and Mn(II), interfere when present in more than 10-fold ratio to Co(II), but several ions can be tolerated when present in higher ratios to Co(II). The concentration range of linear response is from 3.5 x 10(-9) to 2.0 x 10(-6) g/ml, and the detection limit is 4 x 10(-11) g/ml. The procedure has been satisfactorily applied to determine trace cobalt in human blood serum.
Carbon dioxide-enhanced luminol chemiluminescence in the absence of added oxidant
Carbon dioxide significantly enhances the chemiluminescence of 5-amino-2,3-dihydrophthalazine-1,4-dione (luminol) in the absence of added oxidant. The effect in presence of a variety of rate modifiers (e.g., metal ions and some metal ion complexes) is described in detail. A postulation of the species responsible for enhancement, the role of dissolved oxygen, the influence of the form in which the rate modifier is present and a possible mechanism to explain the enhancement by CO2(g), are also presented. The potential analytical applications of this effect are mentioned and illustrated with the analytical figures of merit for the chemiluminescence determination of CoII in the 5 × 10–13–10–7 mol l–1 range.
Peritoneal eosinophils during intermittent peritoneal dialysis.
Peritoneal eosinophil counts were investigated in 61 intermittent dialysis patients over the course of 1 year. The peritoneal eosinophil percentage fell from 18 +/- 2% (mean +/- SEM) in the first 2 months of dialysis to 3 +/- 0.4% after 6 months of dialysis. Absolute eosinophils per cubic millimeter fell from 586 +/- 126 to 61 +/- 18 (p less than 0.01 for both percentage and absolute values). There was a wide range in the mean eosinophil percentages per patient in the first 6 months of dialysis (0-84%) that narrowed to 0-9% after 6 months. The majority of the high initial eosinophil counts resolved after 2 months. Peripheral eosinophilia was seen in 8 of the 10 patients with the highest mean peritoneal eosinophil percentages during the first 2 months of dialysis. Patients who developed peritonitis had a significantly lower percentage of eosinophils in the first 1.5 months of dialysis than patients who did not develop peritonitis. At the time of diagnosis of peritonitis, the peritoneal eosinophil count was near zero. 4 cases of peritoneal eosinophilia which developed after antibiotic therapy are described.