title: A single-wall carbon nanotubes modified edge plane pyrolytic graphite sensor for determination of methylprednisolone in biological fluids.
abstract: An electrochemical protocol based on reduction is developed to determine methylprednisolone using single-wall carbon nanotubes (SWNTs) modified edge plane pyrolytic graphite electrode (EPPGE). To obtain a good sensitivity, instrumental variables were studied using Square Wave Voltammetry (SWV). The voltammetric results indicate that SWNTs modified EPPGE remarkably enhances the reduction of methylprednisolone which leads to considerable improvement of peak current with shift of peak potential to less negative values. The voltammetric current showed a linear response for methylprednisolone concentration in the range 5-500 nM with a sensitivity of 98 nA nM(-1). The limit of detection was estimated to be 4.5x10(-9)M. The developed method is used for the determination of methylprednisolone in pharmaceutical dosages and human blood plasma samples of patients undergoing treatment with methylprednisolone. The major metabolites present in blood plasma did not interfere with the present investigation as they did not exhibit reduction peak in the experimental range used. A comparison of results with high performance liquid chromatography (HPLC) indicates a good agreement.
authors.affiliation: Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee, India. rngcyfcy@iitr.ernet.in
authors.forename: Rajendra N
authors.initials: RN
authors.lastname: Goyal
authors.forename: Sanghamitra
authors.initials: S
authors.lastname: Chatterjee
authors.forename: Anoop Raj Singh
authors.initials: AR
authors.lastname: Rana
mesh_terms: D002244:Carbon / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D004563:Electrochemistry / Q000295:instrumentation / Q000379:methods*; D004566:Electrodes; D005938:Glucocorticoids / Q000097:blood / Q000737:chemistry / Q000378:metabolism; D006108:Graphite / Q000737:chemistry*; D006801:Humans; D008775:Methylprednisolone / Q000097:blood* / Q000737:chemistry / Q000378:metabolism; D037742:Nanotubes, Carbon / Q000737:chemistry*; D015203:Reproducibility of Results
chemical_list: D005938:Glucocorticoids; D037742:Nanotubes, Carbon; C009139:pyrolytic carbon; D002244:Carbon; D006108:Graphite; D008775:Methylprednisolone