与 K~+和 HPO_4~(2-)不同,Na~+和 Cl~-是维持细胞外液渗透压的主要离子,所以血清钠含量也是诊断水、电解质平衡失调的主要依据。临床检验中测定血清钠含量,目前国内多采用浊度法,比色法或火焰光度法。利用离子选择电极测定血钠,国外已有报导,也有了商品仪器,国内亦已进行研究。我们曾以钾电极指示,样品加入法测定血清钾含 Different from K ~ + and HPO_4 ~ (2-), Na ~ + and Cl ~ - are the main ions that maintain the extracellular fluid osmotic pressure. Therefore, serum sodium content is also the main basis for the diagnosis of imbalance of water and electrolyte. Determination of serum sodium in clinical testing, the current domestic use of turbidimetric method, colorimetry or flame photometry. Sodium ion-selective electrode for the determination of sodium, has been reported abroad, but also has the commodity equipment, has also been studied. We have to potassium electrode instructions, sample addition method for determination of serum potassium