Analityczne zastosowanie zjawiska chemiluminescencji. Jony lantanowców(III) i ich kompleksy jako fluorofory w mieszaninach reakcyjnych

The aim of this review is to evaluate the use of chemiluminescence (CL) as the method for determination of a wide group of organic and inorganic compounds. Chemiluminescence can be defined as the light emission resulting from the transition of an electronically excited state produced in a reaction [1, 2]. CL, in spite of complicated processes occurring in reaction systems, has been used since many years in chemical analysis [13, 22, 30]. Although many chemiluminescence reagents investigated, only a limited number, such as luminol, tris(2,2-bipyridyl)ruthenium(III), potassium permanganate and the Fenton reaction, generating chemical sources of reactive oxygen and nitrogen species, were successfully used for analytical applications. The Fenton system Fe(II)/(III).H2O2 is the source reactive oxygen species and hydrogen radicals [52, 53]. Analytical techniques based on CL have been used in, e.g.: pharmacological studies, clinical and environmental diagnostics [14.17, 22.30, 39.47, 62.65]. Ultra-weak intensity of generated emission (1.104 hn ź s.1 ź cm.2) requires very sensitive detectors and special apparatus, as our detection system for CL measurements based on single photon counting [11]. Studies of CL systems characterised by low intensity of the CL emission require the use of sensitizers. Due to their specific luminescence properties, thelanthanide ions, mainly europium(III) and terbium(III) and their complexes, can be successfully used as chemiluminescence fluorophores [11, 57, 71, 75, 76]. Examples of chemiluminescent methods used for determination of organic molecules (aminoacids, antibiotics, chemotherapeutics), based on the lanthanide(III) ions emission, as a result of the energy transfer process from the excited products of the organic molecule oxidation to the Ln(III), are presented [77, 78].