RESUMEN
Flow injection analysis has been applied to the determination of hydrogen peroxide produced by some different species of microalgae. The method is based on the luminol-H(2)O(2) chemiluminescence reaction using Cr(III) as a catalyst. Optimum experimental conditions for the method have been studied and trace amounts of hydrogen peroxide determined with detection limits of 4 10(-8) mol/L. The method using Cr(III) was compared with that using horseradish peroxidase as the catalyst.
Asunto(s)
Eucariontes/química , Análisis de Inyección de Flujo/métodos , Peróxido de Hidrógeno/análisis , Mediciones Luminiscentes , Catálisis , Cromo , Ácido Edético , Eucariontes/metabolismo , Eucariontes/efectos de la radiación , Peroxidasa de Rábano Silvestre , Peróxido de Hidrógeno/metabolismo , Luminol , FotoquímicaRESUMEN
OBJECTIVE: To find the prevalence and aetiology of chronic cardiac failure (CCF) among elderly people in a health area. DESIGN: Retrospective, crossover study. SETTING: Delicias Sur Health Centre, Zaragoza. PATIENTS AND OTHER PARTICIPANTS: A representative sample of the population over 65 registered at the Health Centre. Systematic random sampling: n = 1,635. MEASUREMENTS AND MAIN RESULTS: 104 cases of cardiac failure were identified, which corresponded to a 6.3% (+/- 0.01) prevalence. By age groups, prevalence was 4.5% (+/- 0.01) for the 65-74 group and 8.5% (+/- 0.02) for those over 75. Regarding aetiology, 50.9% was due to arterial hypertension, 21.2% coronary failure, 22.1% valvulopathies and 17.3% reason unknown. CONCLUSIONS: CCF prevalence in the community increases with age and in our ambit exceeds that found in other countries. Almost half the cases are related to arterial hypertension.