Murphy L J, Galley P T
Unit of Metabolic Medicine, St. Mary's Hospital, Paddington, London, UK.
Anal Chem. 1994 Dec 1;66(23):4345-53. doi: 10.1021/ac00095a035.
Human plasma glycerol was determined with a microdialysis electrode, containing the enzymes glycerol kinase and glycerol phosphate oxidase held stationary within the electrode. A microdialysis electrode is essentially a conventional microdialysis probe, with a platinum working electrode inserted into the tip of the dialysis fiber and reference and counter electrodes contained in the upper compartment. The linear range of response to glycerol was directly dependent on the concentration of ATP. At 4 mM ATP, the linear range was 0.5-500 microM. A fast response time of 20 s was obtained. Two types of interferences were observed when plasma glycerol was measured: direct oxidation of interferents at the electrode and attenuation of response to glycerol by reaction with hydrogen peroxide and/or poisoning of the platinum electrode. Ascorbate, urate, and acetaminophen were removed from plasma samples by a pretreatment step involving peroxidase and catalase. Any remaining interferent current was reduced by electropolymerizing o-phenylenediamine onto the platinum electrode. Adsorption of plasma proteins on the dialysis fiber was minimal and was not reduced by the preadsorption of human serum albumin. Very good correlation was obtained between the electrode and the standard spectrophotometric technique for the variation in glycerol concentration with time.
使用微透析电极测定人血浆甘油，该电极含有固定在电极内的甘油激酶和甘油磷酸氧化酶。微透析电极本质上是一个传统的微透析探针，铂工作电极插入透析纤维尖端，参比电极和对电极置于上部隔室中。对甘油的线性响应范围直接取决于ATP的浓度。在4 mM ATP时，线性范围为0.5 - 500 microM。获得了20秒的快速响应时间。测量血浆甘油时观察到两种干扰：干扰物在电极上的直接氧化以及与过氧化氢反应和/或铂电极中毒导致对甘油响应的衰减。通过涉及过氧化物酶和过氧化氢酶的预处理步骤从血浆样品中去除了抗坏血酸盐、尿酸盐和对乙酰氨基酚。通过将邻苯二胺电聚合到铂电极上，降低了任何剩余的干扰电流。血浆蛋白在透析纤维上的吸附极少，并且人血清白蛋白的预吸附并未减少这种吸附。对于甘油浓度随时间变化的情况，该电极与标准分光光度技术之间获得了非常好的相关性。
