The principle of step-scan Fourier transform infrared (FTIR) spectroscopy is introduced. Double modulation step-scan FTIR technique is used to obtain the quantum cascade laser's stacked emission spectra in the time domain. Optical property and thermal accumulation of devices due to large drive current are analyzed. 相似文献
SHR110008 is a representative 9-β-dihydro-9,10-O-acetal taxane with greater anticancer activity and less toxicity than docetaxel. To support a preclinical study of its pharmacokinetics and to predict the effect of 9-β-dihydro-9,10-O-acetal modification on its pharmacokinetic properties, we have developed a sensitive and rapid liquid chromatographic–tandem mass spectrometric method for quantitative analysis of SHR110008 in rat and dog plasma. Plasma was extracted with ethyl acetate. The analytes were separated on a 150 × 4.6 mm i.d., 5 μm particle, reversed-phase C18 column with 90:10 (v/v) methanol–0.1% formic acid as mobile phase at a flow rate of 0.3 mL min−1. Detection was performed by triple-quadrupole tandem mass spectrometry in selected reaction monitoring (SRM) mode with an electrospray ionization source. The precursor-to-product ion transition m/z 933 → 142 was used. The method was validated for accuracy and precision, and linearity in the two matrices was good. Lower limits of quantification (LLOQ) in rat and dog plasma were 5 and 2 ng mL−1, respectively. There were no stability-related problems in the procedure for analysis of SHR110008. The method was successfully used in a preclinical study of the pharmacokinetics of SHR110008 in rats and beagle dogs. The pharmacokinetics of SHR110008 were non-linear in rats and dogs. The elimination half-life ranged from 5.18 to 7.32 h for the rats and from 6.42 to 8.42 h for the dogs.