Synthesis and preliminary analytical evaluation of the chemiluminescence from (4-[4-(dichloromethylsilanyl)-butyl]-4`-methyl-2,2`-bipyridyl)bis(2,2`-bipyridyl)ruthenium(II) covalently bonded to silica particles

This paper describes, for the first time, a simple and effective synthetic route for covalently bonding the chemiluminescence reagent, (4-[4-(dichloromethylsilanyl)-butyl]-4’-methyl-2,2’-bipyridyl)bis(2,2’-bipyridyl)ruthenium(II) onto silica particles. The subsequent preparation of chemically regeneratable detection cells and their preliminary analytical evaluation with both sequential injection analysis and flow injection analysis are also reported. Unoptimised analytical figures of merit were established for standard solutions of codeine and sodium oxalate with detection limits calculated from three times the standard deviation of the blank signal, of 1 × 10^–8 M and 3 × 10^–7 M respectively. The chemically immobilised reagent exhibited some intriguing solvent and kinetic effects, which are also briefly discussed.

Determination of sodium oxalate in Bayer liquor using flow-analysis incorporating an anion exchange column and tris(2,2`-bipyridyl)ruthenium(II) chemiluminescence detection

Semi-automated flow injection instrumentation, incorporating a small anion exchange column coupled with tris(2,2′-bipyridyl)ruthenium(II) (Ru(bipy)₃²⁺) chemiluminescence detection, was configured and utilised to develop rapid methodology for the determination of sodium oxalate in Bayer liquors. The elimination of both negative and positive interferences from aluminium(III) and, as yet, unknown concomitant organic species, respectively are discussed. The robustness of the methodology was considerably enhanced by using the temporally stable form of the chemiluminescence reagent, tris(2,2′-bipyridyl)ruthenium(III) perchlorate in dry acetonitrile. Real Bayer process samples were analysed and the results obtained compared well with those performed using standard methods within industrial laboratories.

Determination of glyphosate mono-isopropylamine salt in process samples using flow injection analysis with tris(2,2`-bipyridyl)ruthenium(II) chemiluminescence detection

The mono-isopropylamine salt of glyphosate was selectively determined directly in industrial and commercial formulations using flow injection analysis with tris(2,2′-bipyridyl)ruthenium(II) chemiluminescence detection without the need for separation. Glyphosate and its mono-isopropylamine salt furnished detection limits of 7×10⁻⁹ and 3.5×10⁻¹⁰ M and relative standard deviations of 0.4% at 1×10⁻⁷ M and 0.8% at 5×10⁻⁸ M, respectively. The methodology is robust and reliable with samples subjected only to aqueous dilution prior to analysis.

Determination of proline in wine using flow injection analysis with tris(2,2`-bipyridyl)ruthenium(II) chemiluminescence detection

Flow injection methodology is described for the determination of proline in red and white wines using tris(2,2′-bipyridyl)ruthenium(II) chemiluminescence detection. Selective conditions were achieved for proline at pH 10, while other amino acids and wine components did not interfere. The precision of the method was less than 1.00% (R.S.D.) for five replicates of a standard (4 × 10⁻⁶ M) and the detection limit was 1 × 10⁻⁸ M. The level of proline in white and sparkling wines using the developed methodology was equivalent to those achieved using HPLC-FMOC amino acid analysis. SPE removal of phenolic material was required for red wines to minimize Ru(bipy)₃³⁺ consumption and its associated effect on accuracy.

Preliminary evaluation of dual acidic potassium permanganate and tris(2,2`-bipyridyl)ruthenium(II) chemiluminescence detection for the HPLC determination of Papaver somniferum alkaloids

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.

Detection of pyrrolizidine alkaloids using flow analysis with both acidic potassium permanganate and tris(2,2’-bipyridyl)ruthenium(II) chemiluminescence

For the first time, analytically useful chemiluminescence was elicited from the reactions of the pyrrolizidine alkaloids. Heliotrine, retronecine, supinine, monocrotaline and echinatine N-oxide yielded chemiluminescence upon reaction with tris(2,2′-bipyridyl)ruthenium(II) whilst lasiocarpine, its N-oxide and supinine elicited light upon reaction with acidic potassium permanganate. Detection limits for heliotrine were 1.25 × 10⁻⁷ M and 9 × 10⁻⁹ M for tris(2,2′-bipyridyl)ruthenium(III) perchlorate with flow injection analysis (FIA) and the silica-immobilised reagent (4-[4-(dichloromethylsilanyl)-butyl]-4′-methyl-2,2′-bipyridine)bis(2,2′-bipyridyl)ruthenium(II) with sequential injection analysis (SIA), respectively. Lasiocarpine was detectable at 1.4 × 10⁻⁷ M using acidic potassium permanganate with FIA. Additionally, the silica-immobilised reagent was optimised with respect to the oxidant (ammonium ceric nitrate) concentration and the aspiration times which afforded a detection limit for codeine of 5 × 10⁻¹⁰ M using SIA.

Determination of psilocin and psilocybin using flow injection analysis with acidic potassium permanganate and tris(2,2’-bipyridyl) ruthenium(II) chemiluminescence detection respectively

A simple, rapid and sensitive method for the determination of psilocin and psilocybin is described. This is the first report on the determination of psilocin and psilocybin using flow injection analysis with acidic potassium permanganate and tris(2,2′-bipyridyl)ruthenium(II) chemiluminescence. The limits of detection (signal-to-noise ratio = 3) are 9 × 10⁻¹⁰ M and 3 × 10⁻¹⁰ M for psilocin and psilocybin, respectively.A concise synthetic route for psilocin in three steps from readily available starting materials is also described. The structures were elucidated on the basis of spectroscopic data.

Tris(2,2´-bipyridyl)ruthenium(II) chemiluminescence

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).

The determination of psilocin and psilocybin in hallucinogenic mushrooms by HPLC utilizing a dual reagent acidic potassium permanganate and tris(2,2´-bipyridyl)ruthenium(II) chemiluminescence detection system

This paper describes a procedure for the determination of psilocin and psilocybin in mushroom extracts using high-performance liquid chromatography with postcolumn chemiluminescence detection. A number of extraction methods for psilocin and psilocybin in hallucinogenic mushrooms were investigated, with a simple methanolic extraction being found to be most effective. Psilocin and psilocybin were extracted from a variety of hallucinogenic mushrooms using methanol. The analytes were separated on a C₁₂ column using a (95:5% v/v) methanol:10 mM ammonium formate, pH 3.5 mobile phase with a run time of 5 min. Detection was realized through a dual reagent chemiluminescence detection system of acidic potassium permanganate and tris(2,2'-bipyridyl)ruthenium(II). The chemiluminescence detection system gave improved detectability when compared with UV absorption at 269 nm, with detection limits of 1.2 × 10⁻⁸ and 3.5 × 10⁻⁹ mol/L being obtained for psilocin and psilocybin, respectively. The procedure was applied to the determination of psilocin and psilocybin in three Australian species of hallucinogenic mushroom.

The voltammetric reduction, deprotonation and surface activity of ruthenium photovoltaic sensitizers in acetone

The reductive voltammetry of the photovoltaic sensitizer [(H2-dcbpy)2Ru(NCS)2] (H2-dcbpy=2,2′-bipyridine-4,4′-dicarboxylic acid) and [(H3-tctpy)Ru(NCS)3]− (H3-tctpy=2,2′:6′,2″-terpyridine-4,4′,4″-tricarboxylic acid) has been investigated in acetone. Significant surface interactions at both platinum and glassy carbon electrodes occur at 0.6 V prior to the reversible potential expected for ligand-based reduction process of the fully protonated acids. The origin of the surface interactions are attributed to the acid–base behaviour of the compounds, combined with overall deprotonation and reduction to hydrogen, since repetitive cycling of the potential reveals well-defined reversible reduction processes in the negative potential range, resulting from formation of doubly deprotonated [(H-dcbpy−)2Ru(NCS)2]2− and singly deprotonated [(H2-tctpy−)Ru(NCS)3]2−, respectively. The extent of the surface interactions has been estimated by electrochemical quartz crystal microbalance and chronocoulometric measurements. Under certain conditions, a thick conducting polymer consisting of several hundred monolayers is formed.

Tris(2,2'-bipyridyl)ruthenium(II) chemiluminescence enhanced by silver nanoparticles

Mixtures of silver(I) and citrate that are used to produce silver nanoparticles evoke intense chemiluminescence with tris(2,2'-bipyridyl)ruthenium(II) and cerium(IV), which can be exploited for the determination of citrate ions and other analytes over a wide concentration range.

Preliminary investigations into tris(2,2'-bipyridyl) ruthenium (III) as a chemiluminescent reagent for the detection of 3,6-diacetylmorphine (heroin) on surfaces

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.

Effect of oxidant type on the chemiluminescence intensity from the reaction of tris(2,2’-biyridyl)ruthenium(III) with various organic acids

An investigation into the chemiluminescence of fourteen organic acids and tris(2,2′-bipyridyl)ruthenium(II) was undertaken. Particular emphasis was placed upon the method of production of the reagent, tris(2,2′-bipyridyl)ruthenium(III), with cerium(IV) sulfate, potassium permanganate, lead dioxide and electrochemical generation. Analytically useful chemiluminescence was observed when Ce(IV) or potassium permanganate were employed as oxidants. The kinetics of analyte oxidation was related to the intensity of the chemiluminescence emission, which increased by three orders of magnitude for tartaric acid after 40 h of oxidation.

Evaluation of tris(4,7-diphenyl-1,10-phenanthrolinedisulfonate)ruthenium(II) as a chemiluminescence reagent

Previous studies have suggested that tris(4,7-diphenyl-1,10-phenanthrolinedisulfonate)ruthenium(II) (Ru(BPS)₃⁴⁻) has great potential as a chemiluminescence reagent in acidic aqueous solution. We have evaluated four different samples of this reagent (two commercially available and two synthesised in our laboratory) in comparison with tris(2,2′-bipyridine)ruthenium(II) (Ru(bipy)₃²⁺) and tris(1,10-phenanthroline)ruthenium(II) (Ru(phen)₃²⁺), using a range of structurally diverse analytes. In general, Ru(BPS)₃⁴⁻ produced more intense chemiluminescence, but the oxidised Ru(BPS)₃³⁻ species is less stable in aqueous solution than Ru(bipy)₃³⁺ and produced a greater blank signal than Ru(bipy)₃³⁺ or Ru(phen)₃³⁺, which had a detrimental effect on sensitivity. Although the complex is often depicted with the sulfonate groups of the BPS ligand in the para position on the phenyl rings, NMR characterisation revealed that the commercially available BPS material used in this study was predominantly the meta isomer.

Preliminary evaluation of monolithic column high-performance liquid chromatography with tris(2,2’-bipyridyl)ruthenium(II) chemiluminescence detection for the determination of quetiapine in human body fluids

High-performance liquid chromatography (HPLC) with tris(2,2-bipyridyl)ruthenium(II) chemiluminescence detection methodology is reported for the determination of the atypical antipsychotic drug quetiapine and the observation of its major active and inactive metabolites in human urine and serum. The method uses a monolithic chromatographic column allowing high flow rates of 3mL min−1 enabling rapid quantification. Flow injection analysis (FIA) with tris(2,2-bipyridyl)ruthenium(II) chemiluminescence detection and HPLC time of flight mass spectrometry (TOF-MS) were used for the determination of quetiapine in a pharmaceutical preparation to establish its suitability as a calibration standard. The limit of detection achieved with FIA was 2×10−11 mol L−1 in simple aqueous solution. The limits of detection achieved with HPLC were 7×10−8 and 2×10−10 mol L−1 in urine and serum, respectively. The calibration range for FIA was between 5×10−9 and 1×10−6 mol L−1. The calibration ranges for HPLC were between 1×10−7–1×10−4 and 1×10−8–1×10−4 mol L−1 in urine and serum, respectively. The quetiapine concentrations in patient samples were found to be 3×10−6 mol L−1 in urine and 7×10−7 mol L−1 in serum. Without the need for preconcentration, the HPLC detection limits compared favourably with those in previously published methodologies. The metabolites were identified using HPLC-TOF-MS.