Neil W. Barnett

A chemically initiated adaptation of the classic [Ru(bipy)₃]²⁺/oxalate electrochemiluminescence coreactant system has revealed the elusive radical intermediates of the light-producing pathway. Oxalyl (HC₂O₄˙) and hydroxyformyl (HCO₂˙) radicals have been captured on a quartz surface and characterised using EPR spectroscopy.

Abstract:  The use of tris(2,2′‐bipyridyl) ruthenium (III) as a chemiluminescent spray reagent spot‐test for heroin is discussed. Two forms of the reagent are investigated an aqueous and an anhydrous where both were found to give vastly different results. The aqueous reagent giving slow, low intensity chemiluminescence whilst the anhydrous reagent gave a fast, bright response in the presence of 3,6‐diacetylmorphine. The anhydrous reagent is less sensitive the slow, intensity response is characteristic of only two opiates tested 3,6‐diacetylmorphine and 3‐monoacetylmorphine.

This paper critically reviews analytical applications of the chemiluminescence from tris(2,2′-bipyridyl)ruthenium(II) and related compounds published in the open literature between mid-1998 and October 2005. Following the introduction, which summarises the reaction chemistry and reagent generation, the review divides into three major sections that focus on: (i) the techniques that utilise this type of detection chemistry, (ii) the range of analytes that can be determined, and (iii) analogues and derivatives of tris(2,2′-bipyridyl)ruthenium(II).

This paper describes a dual chemiluminescence reagent for the determination of the opiate alkaloids morphine, codeine, oripavine, and thebaine in Papaver somniferum extracts. Detection was achieved using a mixture of acidic potassium permanganate and tris(2,2'-bipyridyl)ruthenium(ii), where the former acted as both the oxidant for the latter and as a chemiluminescence reagent in its own right. The analytes were separated on a C8 column using ion-pairing HPLC. The application of the mixed reagent detection compared favourably with results obtained using standard HPLC methodology. Detection limits for the alkaloids were 10-6, 5 × 10-7, 3 × 10-6, and 2 × 10-6 mol L-1 for morphine, codeine, oripavine, and thebaine, respectively.