Ion-pairing high-performance liquid chromatography-ultraviolet （HPLC-UV） methods were developed to determine two commonly used chelating agents, ethylenediaminetetraacetic acid （EDTA） in Abilify （a small molecule...Ion-pairing high-performance liquid chromatography-ultraviolet （HPLC-UV） methods were developed to determine two commonly used chelating agents, ethylenediaminetetraacetic acid （EDTA） in Abilify （a small molecule drug with aripiprazole as the active pharmaceutical ingredient） oral solution and die- thylenetriaminepentaacetic acid （DTPA） in Yervoy （a monoclonal antibody drug with ipilimumab as the active pharmaceutical ingredient） intravenous formulation. Since the analytes, EDTA and DTPA, do not contain chromophores, transition metal ions （Cu2＋, Fe3＋） which generate highly stable metallocom- plexes with the chelating agents were added into the sample preparation to enhance UV detection. The use of metallocomplexes with ion-pairing chromatography provides the ability to achieve the desired sensitivity and selectivity in the development of the method. Specifically, the sample preparation in- volving metallocomplex formation allowed sensitive UV detection. Copper was utilized for the de- termination of EDTA and iron was utilized for the determination of DTPA. In the case of EDTA, a gradient mobile phase separated the components of the formulation from the analyte. In the method for DTPA, the active drug substance, ipilimumab, was eluted in the void. In addition, the optimization of the concentration of the ion-pairing reagent was discussed as a means of enhancing the retention of the aminopolycarboxylic acids （APCAs） including EDTA and DTPA and the specificity of the method. The analytical method development was designed based on the chromatographic properties of the analytes, the nature of the sample matrix and the intended purpose of the method. Validation data were presented for the two methods. Finally, both methods were successfully utilized in determining the fate of the chelates.展开更多
A specific, precise and accurate ion-pair HPLC-UV method has been developed and validated for simultaneous determination of phosphocreatine (PCr), and its metabolite creatine (Cr) as well as related ATP in plasma and ...A specific, precise and accurate ion-pair HPLC-UV method has been developed and validated for simultaneous determination of phosphocreatine (PCr), and its metabolite creatine (Cr) as well as related ATP in plasma and red blood cell (RBC) of rabbits. After addition of TMP as IS, the samples were deproteinized with 6% PCA. The analytes were separated on a Kromasil C18 column using a tertiary gradient mobile phase composed of buffer A (0.2% KH2PO4 + 0.08% tetrabutyl ammonium hydrogen sulphate, pH 3.0), buffer B (buffer A adjusted to pH 7.5 with 1 mol/L NaOH) and MeOH. Detection wavelengths were set at 210 nm for PCr and Cr and 260 nm for ATP and TMP. Some blank samples were initially run for baseline subtraction. The linear detection responses were obtained for PCr concentration over a range of 10 - 7500 mg/ml (plasma) and 5 - 2500 mg/ml (RBC) and for both Cr and ATP concentrations of 10 - 1500 mg/ml (plasma) and 5 - 750 mg/ml (RBC) (r > 0.99). The QC samples of 3 analytes showed intra-day and inter-day precisions (RSD) of - 107%. The method was successfully used to simultaneously determine plasma and RBC concentrations of the 3 analytes and to study pharmacokinetics after iv administration of PCr to rabbits.展开更多
A novel reserved\|phase ion\|pair liquid chromatographic method using hexadecyltrimethylammonium bromide（HTMAB） as an ion\|pair reagent for separating the complexes of metal and 8\|hydroxyquinoline\|5\|sulphonic aci...A novel reserved\|phase ion\|pair liquid chromatographic method using hexadecyltrimethylammonium bromide（HTMAB） as an ion\|pair reagent for separating the complexes of metal and 8\|hydroxyquinoline\|5\|sulphonic acid（HQS） coupled with on\|line fluorescence detection has been developed. The chromatographic behavior of metal\|HQS complexes in the proposed system was systematically investigated.When the C\-\{18\} column modified by HTMAB and the suitable mobile phase coupled with fluorescence detection（\%λ\%\-\{ex\}=388 nm; \%λ\%\-\{em\}=518 nm） were employed, the detection limit of cadmium is 7.72 ng/mL with an injection volume of 20 μL, and the linear range of calibration curve for cadmium is 50\800 ng/mL. It was successfully applied to determination of bio\|available cadmium in polluted soils of China. Moreover, the possible species of Cd\|HQS on the column has been investigated by log\|log plot analysis.展开更多
建立了HPLC-ELSD法测定磷霉素钠中磷霉素及有关物质的含量。采用ODS柱,柱温35℃,以0.015m o l/L正辛胺溶液(用冰乙酸调节pH至5.2)∶乙腈(90∶10)为流动相,蒸发光散射检测器温度为45℃,雾化气体压力为0.35M Pa。磷霉素及其二醇物分别在2...建立了HPLC-ELSD法测定磷霉素钠中磷霉素及有关物质的含量。采用ODS柱,柱温35℃,以0.015m o l/L正辛胺溶液(用冰乙酸调节pH至5.2)∶乙腈(90∶10)为流动相,蒸发光散射检测器温度为45℃,雾化气体压力为0.35M Pa。磷霉素及其二醇物分别在26.0～207.7和7.6～60.6μg/m l范围内呈良好的线性关系,两者的定量限分别为8.7和7.7μg/m l。展开更多
A simple and sensitive ion-paring HPLC-MS/MS method with negative ion mode has been developed and validated for the quantification of SA in milk.The separation was performed on C18 column with a mobile phase consistin...A simple and sensitive ion-paring HPLC-MS/MS method with negative ion mode has been developed and validated for the quantification of SA in milk.The separation was performed on C18 column with a mobile phase consisting of 4 mmol/L tetrabutylammonium hydroxide-methanol at a flow rate of 0.2 mL/min under the gradient elution.The retention time of SA was 6.1 min.Triple-quadrupole MS/MS detection was operated in negative mode by monitoring the transition of m/z 308.1>87.1 for SA.Validation results indicated that the lower limit of quantification was 0.060 mg/L and the assay showed a linear range of 0.1-100 mg/L and gave a correlation coefficient(r) of 0.998.The relative standard deviations were less than 10% at all tested concentration levels.The method has been successfully applied to the analysis of SA in milk,milk powder and breast milk.展开更多
文摘Ion-pairing high-performance liquid chromatography-ultraviolet （HPLC-UV） methods were developed to determine two commonly used chelating agents, ethylenediaminetetraacetic acid （EDTA） in Abilify （a small molecule drug with aripiprazole as the active pharmaceutical ingredient） oral solution and die- thylenetriaminepentaacetic acid （DTPA） in Yervoy （a monoclonal antibody drug with ipilimumab as the active pharmaceutical ingredient） intravenous formulation. Since the analytes, EDTA and DTPA, do not contain chromophores, transition metal ions （Cu2＋, Fe3＋） which generate highly stable metallocom- plexes with the chelating agents were added into the sample preparation to enhance UV detection. The use of metallocomplexes with ion-pairing chromatography provides the ability to achieve the desired sensitivity and selectivity in the development of the method. Specifically, the sample preparation in- volving metallocomplex formation allowed sensitive UV detection. Copper was utilized for the de- termination of EDTA and iron was utilized for the determination of DTPA. In the case of EDTA, a gradient mobile phase separated the components of the formulation from the analyte. In the method for DTPA, the active drug substance, ipilimumab, was eluted in the void. In addition, the optimization of the concentration of the ion-pairing reagent was discussed as a means of enhancing the retention of the aminopolycarboxylic acids （APCAs） including EDTA and DTPA and the specificity of the method. The analytical method development was designed based on the chromatographic properties of the analytes, the nature of the sample matrix and the intended purpose of the method. Validation data were presented for the two methods. Finally, both methods were successfully utilized in determining the fate of the chelates.
文摘A specific, precise and accurate ion-pair HPLC-UV method has been developed and validated for simultaneous determination of phosphocreatine (PCr), and its metabolite creatine (Cr) as well as related ATP in plasma and red blood cell (RBC) of rabbits. After addition of TMP as IS, the samples were deproteinized with 6% PCA. The analytes were separated on a Kromasil C18 column using a tertiary gradient mobile phase composed of buffer A (0.2% KH2PO4 + 0.08% tetrabutyl ammonium hydrogen sulphate, pH 3.0), buffer B (buffer A adjusted to pH 7.5 with 1 mol/L NaOH) and MeOH. Detection wavelengths were set at 210 nm for PCr and Cr and 260 nm for ATP and TMP. Some blank samples were initially run for baseline subtraction. The linear detection responses were obtained for PCr concentration over a range of 10 - 7500 mg/ml (plasma) and 5 - 2500 mg/ml (RBC) and for both Cr and ATP concentrations of 10 - 1500 mg/ml (plasma) and 5 - 750 mg/ml (RBC) (r > 0.99). The QC samples of 3 analytes showed intra-day and inter-day precisions (RSD) of - 107%. The method was successfully used to simultaneously determine plasma and RBC concentrations of the 3 analytes and to study pharmacokinetics after iv administration of PCr to rabbits.
文摘A novel reserved\|phase ion\|pair liquid chromatographic method using hexadecyltrimethylammonium bromide（HTMAB） as an ion\|pair reagent for separating the complexes of metal and 8\|hydroxyquinoline\|5\|sulphonic acid（HQS） coupled with on\|line fluorescence detection has been developed. The chromatographic behavior of metal\|HQS complexes in the proposed system was systematically investigated.When the C\-\{18\} column modified by HTMAB and the suitable mobile phase coupled with fluorescence detection（\%λ\%\-\{ex\}=388 nm; \%λ\%\-\{em\}=518 nm） were employed, the detection limit of cadmium is 7.72 ng/mL with an injection volume of 20 μL, and the linear range of calibration curve for cadmium is 50\800 ng/mL. It was successfully applied to determination of bio\|available cadmium in polluted soils of China. Moreover, the possible species of Cd\|HQS on the column has been investigated by log\|log plot analysis.
文摘A simple and sensitive ion-paring HPLC-MS/MS method with negative ion mode has been developed and validated for the quantification of SA in milk.The separation was performed on C18 column with a mobile phase consisting of 4 mmol/L tetrabutylammonium hydroxide-methanol at a flow rate of 0.2 mL/min under the gradient elution.The retention time of SA was 6.1 min.Triple-quadrupole MS/MS detection was operated in negative mode by monitoring the transition of m/z 308.1>87.1 for SA.Validation results indicated that the lower limit of quantification was 0.060 mg/L and the assay showed a linear range of 0.1-100 mg/L and gave a correlation coefficient(r) of 0.998.The relative standard deviations were less than 10% at all tested concentration levels.The method has been successfully applied to the analysis of SA in milk,milk powder and breast milk.
