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).

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

Coreactants of tris(2,2′-bipyridyl)ruthenium(II) Electrogenerated Chemiluminescence

A novel method for highly sensitive detection of primary and secondary amino acids with selective derivatization using acetaldehyde as a new derivatization reagent was proposed by capillary electrophoresis (CE) coupled with electrogenerated chemiluminescence (ECL) of tris(2,2‘-bipyridine)ruthenium(II). The precolumn derivatization of these amino acids with acetaldehyde was performed in aqueous solution at room temperature for 1 h. Upon optimized derivatization, the ECL intensities and detection sensitivities of the amino acids were significantly enhanced by 20−70 times. Using four amino acids, arginine, proline, valine, and leucine, as model compounds, their derivatives could be completely separated by CE and sensitively detected by ECL within 22 min. The linear ranges were 0.5−100 μM for arginine and proline and 5−1000 μM for valine and leucine with the detection limits of 1 × 10-7 (0.5 fmol, arginine), 8 × 10-8 (0.4 fmol, proline), 1 × 10-6 (5 fmol, valine), and 1.6 × 10-6 M (8 fmol, leucine) at a signa...

Electrogenerated chemiluminescence detection of amino acids based on precolumn derivatization coupled with capillary electrophoresis separation.

capillary electrophoresis (CE) is characterized. A 300 mum diameter Pt working electrode was used to directly couple with a 75 mum inner diameter separation capillary without an electric field decoupler. The hydrodynamic cyclic voltammogram (CV) of Ru(bpy)(3)(2+) showed that electrophoretic current did not affect the ECL reaction. The presence of high-voltage (HV) field only resulted in the shift of the ECL detection potential. The distance of capillary to electrode was an important parameter for optimizing detection performance as it determined the characteristics of mass transport toward the electrode and the actual concentration of Ru(bpy)(3)(2+) in the detection region. The optimum distance of capillary to electrode was decided by the inner diameter of the capillary, too. For a 75 mum capillary, the working electrode should be placed away from the capillary outlet at a distance within the range of 20-260 mum. The effects of pH value of ECL solution and molecular structure of analytes on peak height and theoretical plate numbers were discussed. Using the 75 mum capillary, under the optimum conditions, the method provided a linear range for tripropylamine (TPA) between 1 x 10(-10) and 1 X 10(-5) mol/L with correlation coefficient of 0.998. The detection limit (signal-to-noise ratio S/N = 3) was 5.0 x 10(-11) mol/L. The relative standard deviation in peak height for eight consecutive injections was 5.6%. By this new technique lidocaine spiked in a urine sample was determined. The method exhibited the linear range for lidocaine from 5.0 x 10(-8) to 1.0 X 10(-5) mol/L with correlation efficient of 0.998. The limit of detection (S/N = 3) was 2.0 x 10(-1) mol/L.

New technique for capillary electrophoresis directly coupled with end-column electrochemiluminescence detection.

Determination of diphenhydramine by capillary electrophoresis with tris(2,2'-bipyridyl)ruthenium(II) electrochemiluminescence detection.

Compositional analysis of small peptides using capillary electrophoresis and Ru(bpy)33+-based chemiluminescence detection

Objective: Intravenous injection of Dodecafluoropentane emulsion (DDFPe) increases oxygen transportation and reduces brain infarct volume in rabbit stroke models. Many potential applications in stroke, blood loss, ischemic states, and high risk angiography are yet undefined. Previous studies suggested a blood elimination half-life of 90 min after injection. In this report, we show a two-phase DDFP pharmacokinetic profile with rapid distribution and longer elimination half-life.

Methods: New Zealand White rabbits (N=6) were administered an I.V. bolus of DDFPe (12 mg DDFP/kg). Blood samples were taken at pre-dose and then every 3-min for 40 min following the dose. Samples were transferred to headspace vials and stored at -20 0C until analyzed by headspace sampling coupled to GC-MS analysis. Pharmacokinetic parameters were determined using compartmental analysis with exponential terms calculated using the curve-stripping method (PK Solutions 2.0).

Results: A 2-compartment model was the best fit to the DDFP blood concentration-time profiles in each of the animals tested. A rapid distribution phase followed by a longer elimination phase was observed. The distribution phase half-life was 1.15 ± 0.6 min, while the elimination half-life was 13.5 ± 11 min (N=4).

Conclusions: A traditional serum pharmacokinetic approach toward development of proper dosing regimens for DDFPe stroke therapy is not feasible given the short half-life relative to the known pharmacodynamic model that shows efficacy for 90-min following a dose of DDFPe. Organ specific pharmacokinetics of DDFP in tissues such as the brain will likely lead to more effective pharmacokinetic models of DDFP following administration of DDFPe.

Howard P Hendrickson

Papers

Compositional analysis of small peptides using capillary electrophoresis and Ru(bpy)33+-based chemiluminescence detection

Abstract T P93: Blood Pharmacokinetics Of Dodecafluoropentane Following Administration Of Dodecafluoropentane Emulsion To Rabbits