Matson W R, Langlais P, Volicer L, Gamache P H, Bird E, Mark K A
Clin Chem. 1984 Sep;30(9):1477-88.
Coulometric electrodes in series have been used with liquid chromatography with electrochemical detection to increase selectivity and resolution for the direct analysis of tissue neurotransmitters. Use of three coulometric sensors for electrochemical modification, selectivity, and peak identification has been expanded into "gate" cells of three or four coulometric electrodes that allow elimination of all electrochemically irreversible substances, and "array" cells of up to 15 coulometric electrodes for separation of co-eluting compounds by their current/voltage characteristics. On-column sensitivity of the sensor arrays is 0.4 to 4 pg. Gate cell selectivity favors electrochemically reversible compounds over irreversible ones, e.g., 3-methoxy-4-hydroxyphenylglycol vs ascorbate, by a factor of up to 10(4). Resolution across the multi-electrode array cells allows separation of co-eluting compounds with half-wave potentials differing by as little as 30 to 40 mV. Cells with three to 15 electrodes have been used to measure monoamines and metabolites in brain; monoamines directly in serum filtrate; and the state of oxidation of 5-hydroxytryptamine and 5-hydroxytryptophan in cerebrospinal fluid of patients with Alzheimer's disease.
串联式库仑电极已与液相色谱-电化学检测联用，以提高对组织神经递质直接分析的选择性和分辨率。将三个用于电化学修饰、选择性和峰识别的库仑传感器应用扩展到由三或四个库仑电极组成的“门”型电解池，可消除所有电化学不可逆物质；以及扩展到由多达15个库仑电极组成的“阵列”型电解池，用于根据共洗脱化合物的电流/电压特性对其进行分离。传感器阵列的柱上灵敏度为0.4至4皮克。“门”型电解池的选择性有利于电化学可逆化合物而非不可逆化合物，例如3-甲氧基-4-羟基苯乙二醇与抗坏血酸相比，优势高达10⁴倍。通过多电极阵列电解池可实现半波电位相差低至30至40毫伏的共洗脱化合物的分离。已使用具有三至15个电极的电解池来测量脑中的单胺和代谢物；直接测量血清滤液中的单胺；以及阿尔茨海默病患者脑脊液中5-羟色胺和5-羟色氨酸的氧化状态。
