ABSTRACT
OBJECTIVE:To provide theoretical basis for the detection of paracetamol by infrared spectroscopy. METHODS:0.002-0.02 g paracetamol was accurately weighed,added into 0.2 g potassium bromide,respectively,fully ground and well mixed, potassium bromide pressing plate method was used for to-be-tested test sample. Using hollow cathode lamp as light,scanning fre-quency was 30 times,resolution was 0.5 cm-1,scan range was 4000-400 cm-1,infrared absorption spectrum was determined and recorded to select the characteristic absorption peaks,then determine the optimized characteristic absorption peaks. Linear and non-linear models were respectively established by using mathematics modeling methods. RESULTS:1 016 cm-1 absorption peak with weaker absorbance but stronger features was selected for the analysis. According to the model establishing and calculation,the accu-racy of the nonlinear model was much higher than the linear model,r=0.942. CONCLUSIONS:Nonlinear quantitative model for quantitatively determining the content of paracetamol is feasible,and suitable for the on-destructive and rapid on-line quality control of paracetamol.
ABSTRACT
In this study, the adsorption behavior of epirubicin hydrochloride (EPI) on carboxylated single-walled carbon nanotubes (c-SWNTs) obtained by mixture acid treatment was investigated. The results indicated that the dispersion of c-SWNTs in water was obviously improved. The absorption of EPI on c-SWNTs came to equilibrium after 240 min and could be explained by pseudo-second-order model. Moreover, there were heterogeneous distribution of active sites onto c-SWNTs surface and the Freundlich isotherm model was better fit to describe the absorption precess of EPI on c-SWNTs. The absorption capacity of EPI on c-SWNTs increased obviously with the increasing pH and decreasing temperature. Compared with multi-walled carbon nanotubes, carboxylated multi-walled carbon nanotubes, SWNTs, c-SWNTs possessed higher absorption capacity for EPI. The controlled, targeted and sustained release of EPI from c-SWNTs-EPI could be instructive for the development of nano-carrier.