Determination of trace amounts of total arsenic in environmental samples by hydride generation flow injection-AAS using a mixed acid as a pretreatment agent.

A method is described for the determination of total arsenic by hydride generation-atomic absorption spectrophotometry using a mixed acid as a pretreatment. Hydride generation is done by the flow-injection method. The authors investigated in detail the temperature and time of decomposition using inorganic, organic arsenic and environmental standard samples, pretreated with nitric-perchloric-sulfuric mixed acid. By using a mixed acid as a pretreatment agent at 220 degrees C, the decomposition time could be shortened and the blank value of arsenic from the reagents used was reduced. The mixed acid of nitric-perchloric-sulfuric was also found to be effective as a pretreatment agent for organic arsenic compounds in which a dimethylated compound, sodium cacodylate or biological samples, is known to be one of the indecomposables. The present approach was proved to be satisfactory as a pretreatment for the quantitative analysis of trace amounts of total arsenic in liquid or solid environmental samples, such as geothermal water, sediments and biological samples.

[Evaluation of risks for postoperative pulmonary complications using a preoperative consultation system].

We retrospectively investigated the perioperative management and postoperative pulmonary complications of patients who had preoperative respiratory problems and consultations with anesthesiologists. These patients numbered eight hundred, 23.7% of all patients who had preoperative consultations, and 40.9% and 62.0% of the 800 had preoperative and postoperative respiratory management, respectively. Forty eight patients (6.0%) received postoperative artificial respiration. One hundred and twenty four patients (15.5%) had some respiratory complications post-operatively, and 5 patients (0.7%) died mainly because of the complications. In an evaluation of these patients with the modified predicted risk factors of Okutsu including the obesity factor and smoking history, there was no respiratory complication in patients under 14 points. Patients with high points of more than 20 included almost all of the patients (114 patients, 91.9%) who had postoperative respiratory complications. We conclude that our preoperative consultation system works well and that the modified predicted-risk factors for postoperative pulmonary complications is useful for the standardization and objectivity of preoperative patient evaluation.