49 research outputs found
Methods for direct determination of mitomycin C in aqueous solutions and in urine
Stripping voltammetry (SV) is used to quantitatively determine concentrations of the anti-neoplastic drug mitomycin C (MMC) alone and in mixtures with 5-fluorouracil and cisplatin, both of which are used in combined chemotherapy with MMC. If the accumulation is performed at the potentials of MMC reduction (-0.35 V vs. SCE), reduced MMC is strongly adsorbed at the electrode. It is possible to prepare a MMC-modified electrode, which, after a washing step, is transferred to the background electrolyte to determine MMC by voltammetry. This procedure, which is termed transfer stripping voltammetry (TSV), helps to eliminate interferences and can be applied for a direct determination of MMC alone or in mixtures with other drugs in urine
The autoderivatization of cyclophosphamide and its metabolite 4-keto cyclophosphamide during capillary gas chromatography
The selectivity of a capillary gas chromatographic assay for the antineoplastic and immunosuppressive agent cyclophosphamide (CPA) towards one of its naturally occurring metabolites, i.e. 4-keto cyclophosphamide (4-keto CPA), has been studied.
Mass spectrometry studies revealed that a cyclization product of 4-keto CPA can be formed during the same chromatographic conditions under which CPA has been determined. However, the produced amount is relatively small (less than 10%) in comparison with the percentage produced from CPA. Furthermore, both cyclization products, formed by a loss of HCI and intra alkylation of the parent compounds, can be well separated under proper chromatographic conditions
The autoderivatization of 4-ketocyclophosphamide during capillary gas chromatography
The selectivity of a capillary gas chromatographic assay for the anti-neoplastic and immunosuppressive agent cyclophosphamide (CPA) towards one of its naturally occurring metabolites, i.e. 4-ketocyclophosphamide (4-keto CPA), has been studied. Mass spectrometry studies showed that a cyclization product of 4-keto-CPA can form using the same chromatographic conditions as those under which CPA was determined. However, the amount produced is relatively small (less than 10%) compared with the percentage produced from CPA. Furthermore, both cyclization products, formed by loss of HCI and intraalkylation of the parent compounds, can be separated well under suitable chromatographic conditions
Mass Spectrometry-based bioassay for the screening of soluble orphan receptors
The suitability of a novel mass spectrometric (MS) based flow-injection bioassay format to rapidly detect ligands for soluble orphan receptors in complex matrices was demonstrated, using digoxin and antidigoxigenin FAb as the model ligand and the model protein target, respectively. In addition, characteristic MS and M