Figure 1.2.1 - Detector flow cells with amalgam electrodes. THIN LAYER(A): (1) outlet, (2) hole for RE, (3) inlet, (4) steel block – CE, (5) PTFE gasket, (6) WE, (7) contact – Pt wire, (8) PTFE body of WE; WALL JET (B): (1) inlet, (2) overflow vessel, (3) outlet, (4) Pt wire CE, (5) WE, (6) RE; CYLINDRICAL (C): (1) WE, (2) PTFE tube; TUBULAR (D): (1) inlet, (2) contact – Pt wire, (3) WE, (4) sleeve – PTFE tube, (5) PTFE tube, (6) outlet.
group is irreversibly reduced to a nitro anion radical first (earlier also observed at silver and other solid electrodes) and than the nitro anion radical is reduced to hydroxylamine with the exchange of three electrons [12]. AgSAE was found to be suitable for the determination of submicromolar concentrations of a number of azodyes [13]. Voltammetric and amperometric methods using AgSAE for detection of selected nitro and/or heterocyclic herbicides were developed with LoD in the range of 10-6 - 10-8 mol l-1. Different types of AgSAE were utilized for the determination of 1,3-dinitrobenzene and 2,4-dinitrotoluene, 2- and 4-nitrophenol, 2-methoxy-5-nitrophenol, and 2,4-dinitrophenol. A mixture of selected nitrophenols was also determined by means of an amperometric detector utilizing p-AgSAE in a wall jet and thin layer arrangement after HPLC separation. 2-Methyl-4,6-dinitrophenol, Pendimethalin, Bifenox [14,15], Nitrophen, acifluorphen and oxyfluorphen [16] were also determined in mixture by HPLCED using wall jet and tubular AgSAE. Bipyrylidium herbicide Diquat was determined using dental amalgam electrode and the developed method was used for determination of Diquat in water samples and potatoes. [17]. Examples of easily electrochemically reducible antineoplastic drugs are derivatives of nitrosourea. Carmustine and Lomustine were determined using voltammetry at m-AgSAE with LoD 10-7 mol l-1 [18]. FIA and HPLC systems with amperometric detection in wall jet arrangements were successfully used for fast and automated analysis of high number of Carmustine samples with LoD around 10-6 mol l-1 [19]. Structurally similar Streptozotocin was also determined at SAE. The