Fluorescein and its derivatives, including 4′,5′–dibromofluorescein, 2′,7′–dichlorofluorescein and 2′,4′,5′,7′–tetrabromofluorescein can be employed as efficient coreactants for luminol reaction. Under an alkaline condition they reacted with luminol to produce measureable chemiluminescence (CL) in the absence of any extra–oxidant. Cobalt ion (Co²⁺) significantly enhanced the CL emission of the reaction. The CL emission was strongly dependent on the concentration of carbonate buffer used; higher concentration of carbonate buffer provided more intense CL emission. The system had two emission peaks locating at 425 nm and 535 nm, respectively. With 4′,5′–dibromofluorescein as the coreactant for luminol reaction, a new CL method was developed for the detection of Co²⁺. The procedure allowed the linear detection of Co²⁺ in the range of 5–1000 nmol/L. The limit of detection (LOD) and limit of quantitation (LOQ) were 1.8 nmol/L and 5.0 nmol/L, respectively. The intra–day precision (n = 11) and inter–day precision (n = 3) was 3.2% and 4.7% for replicated measurements of 0.2 μmol/L Co²⁺ solution. The method was successfully applied to the determination of Co²⁺ in blue silica gel samples.

荧光素及其衍生物，包括4'，5'-二溴荧光素，2'，7'-二氯荧光素和2'，4'，5'，7'-四溴荧光素可用作鲁米诺反应的有效共反应剂。在碱性条件下，它们在没有任何额外氧化剂的情况下与鲁米诺反应生成可测量的化学发光（CL）。钴离子（Co ²⁺）显着增强了反应的CL发射。CL排放在很大程度上取决于所用碳酸盐缓冲液的浓度。较高浓度的碳酸盐缓冲液可提供更强的CL发射。该系统有两个分别位于425 nm和535 nm的发射峰。以4'，5'-二溴荧光素为鲁米诺反应的共反应剂，开发了一种新的CL方法用于检测Co ²⁺。该程序允许在5–1000 nmol / L范围内线性检测Co ²⁺。检测限（LOD）和定量限（LOQ）分别为1.8 nmol / L和5.0 nmol / L。对于0.2μmol/ L Co ²⁺溶液的重复测量，日内精度（n = 11）和日间精度（n = 3）为3.2％和4.7％。该方法成功地用于蓝色硅胶样品中Co ^2+的测定。