Xu Chao, Qin Yu, Bakker Eric
Department of Chemistry, Auburn University, 179 Chemistry Bldg, Auburn, AL 36849, USA.
Talanta. 2004 May 10;63(1):180-4. doi: 10.1016/j.talanta.2003.10.033.
Bulk optodes for monovalent ions typically exhibit a relatively narrow measuring range of about two-orders of magnitude. Here, the measuring range was expanded to about six-orders of magnitude concentration change by optimizing a fluorescent chloride optical sensing film based on a plasticized poly(vinyl chloride) film incorporating the halide-selective ionophore [9]mercuracarborand-3 and the H(+)-chromoionophore 9-dimethylamino-5-[4-(15-butyl-1,13-dioxo-2,14-dioxanonadecyl) phenyl-imino]benzo[a]phenox-azine (ETH 5418). This was achieved with the recently established two-step ionophore binding mechanism: the expanded sensing range sequentially makes use of the 1:2 and 1:1 binding stoichiometries between ionophore to chloride. The relevant complex formation constants were found here as logK(1)=9.1 and logK(2)=2.7, which are consistent with previously reported values. The selectivity of this optode is very good, with an excellent discrimination of thiocyanate and lipophilic anions such as salicylate, nitrate and perchlorate. As with earlier work, the main interferences are the other halides bromide and iodide.
用于单价离子的批量光极通常显示出相对较窄的测量范围，约为两个数量级。在此，通过优化基于增塑聚氯乙烯膜的荧光氯化物光学传感膜，将测量范围扩展到约六个数量级的浓度变化，该膜包含卤化物选择性离子载体[9]汞碳硼烷-3和H(+)-发色离子载体9-二甲基氨基-5-[4-(15-丁基-1,13-二氧代-2,14-二氧杂十九烷基)苯基-亚氨基]苯并[a]吩恶嗪(ETH 5418)。这是通过最近建立的两步离子载体结合机制实现的：扩展的传感范围依次利用离子载体与氯化物之间1:2和1:1的结合化学计量。在此发现相关的络合物形成常数为logK(1)=9.1和logK(2)=2.7，这与先前报道的值一致。该光极的选择性非常好，对硫氰酸盐和亲脂性阴离子如水杨酸盐、硝酸盐和高氯酸盐有出色的区分能力。与早期工作一样，主要干扰物是其他卤化物溴化物和碘化物。
