Muñoz de la Peña A, Pérez Rodríguez M, Escandar G M
Department of Analytical Chemistry, University of Extremadura, 06071 Badajoz, Spain.
Talanta. 2000 Apr 28;51(5):949-55.
The influence of different factors on the room-temperature phosphorescence (RTP) emission from the inclusion complex between alpha-cyclodextrin (alpha-CD) and 6-bromo-2-naphthol (BN) was analyzed. Although RTP signals are detected even in aerated solutions, an efficient enhancement of the phosphorescence emission (about 13 times) is obtained when the solutions of the complex are deaerated with nitrogen bubbling, while quenching is produced when sodium sulfite is used for deoxygenation. Association constants of the 1:1 and 2:1 alpha-CD-BN complexes have been evaluated by molecular absorption and fluorimetric methods. Exciting at 287 nm, the RTP phosphorescence emission showed two maxima located at 500 and 535 nm and a shoulder at 577 nm. The RTP emission increases with the irradiation time of the sample by the xenon lamp of the fluorimeter, until it achieves a constant value after around 10 min of irradiation. The addition of organic molecules such as alcohols and bromoalcohols as a third component of the system produces an enhancement of the RTP emission smaller than that obtained in the absence of them. The calibration graph for BN was linear for the range of concentrations between 0.4 and 2.0 mug ml(-1) with a detection limit of 0.26 mug ml(-1), with relative standard deviation (RSD) (n=6) of 4%, for 1.6 mug ml(-1). The solution was transparent, and there was no precipitation.
分析了不同因素对α-环糊精（α-CD）与6-溴-2-萘酚（BN）包合物室温磷光（RTP）发射的影响。尽管即使在曝气溶液中也能检测到RTP信号，但当用氮气鼓泡对配合物溶液进行除气时，磷光发射会有效增强（约13倍），而当使用亚硫酸钠进行脱氧时则会产生猝灭。通过分子吸收和荧光法评估了1:1和2:1的α-CD - BN配合物的缔合常数。在287 nm处激发时，RTP磷光发射显示出两个最大值，分别位于500和535 nm处，以及在577 nm处有一个肩峰。RTP发射随样品被荧光计的氙灯照射时间的增加而增加，直到照射约10分钟后达到恒定值。加入醇类和溴代醇类等有机分子作为体系的第三组分时，RTP发射的增强程度小于未加入时。BN的校准曲线在浓度范围为0.4至2.0 μg ml⁻¹时呈线性，检测限为0.26 μg ml⁻¹，对于1.6 μg ml⁻¹，相对标准偏差（RSD）（n = 6）为4%。溶液是透明的，没有沉淀。
