中文摘要：

采用间甲酚紫和百里酚蓝指示剂，对2011年9～11月在胶州湾及2012年4月在青岛近海采集的表层水样使用分光光度法测定pH，与电极电位法进行互校。通过对53个样品、144个数据进行分析，结果发现分光光度法测定值一般低于电极电位法，间甲酚紫为指示剂的测定值与电极电位法测定值的差值为0．104±0．027，百里酚蓝为0．103±0．057。电极电位法分析得到2011年胶州湾秋季表层海水PH范围是7．641～8．158，平均为7．947±0．118，青岛近海海水pH范围是7．949～8．087，平均为8．052±0．046。通过对近几年胶州湾及青岛近海海水pH的分析，2007（2011年表层海水pH值呈先升后降，总体下降了0．06±0．05；胶州湾红岛海域在2003-2011年pH值变化趋势是先下降后升高再下降，目前pH值较2003年下降了0．09；大沽河附近海域2006-2011年pH值变化趋势与红岛海域基本一致；青岛近海pH值较2003年仅下降0．02。胶州湾及青岛近海海水pH值总体上呈现下降的趋势

英文摘要：

It is compared pH measured by spectrophotometric and potentiometrie methods for seawater samples which were collected in Jiaozhou Bay in autumn, 2011 and Qingdao coast on april 15th of 2012. 53 samples were analyzed and found that the pH values obtained by potentiometric measurements were higher than those by spectrophotometric method and the average of difference between two methods was 0. 104±0. 027. The data showed that pH of Jiaozuo Bay varied from 7. 862 to 8. 049 and the aver- age was 7. 946±0. 056. The range of pH in coastal waters of Qingdao was 7. 949-8. 087 and the aver- age was 8. 052 0. 046. In comparison with historical data, it is found there was a little variation of pH values. ThepH value of surface seawater inJiaozhou Bay in autumn o{2007~2011 descended at first and then ascended and in the last descened by 0.06 0.05. The pH of Hongdao region descended at first and then ascended and in the last descened by 0.09. The pH value at the adjacent sea area of Dagu Riv er had the similar trend to that of Hongdao area. The pH in coastal waters of Qingdao had varied only 0.02 compared with 2003. The pH inJiaozhou Bay and coastal waters of Qingdao presented a decrea sing trend on the whole.