Fabrication of MIL-101(Cr)/silver nanocomposites as SERS substrate for sensitive determination of malachite green and crystal violet in tilapia.

Nanocomposites with multiple functions have attracted much attention in designing novel SERS substrates. In this report, the enrichment ability of MIL-101(Cr) and the local surface plasma resonance (LSPR) of silver nanoparticles are combined to fabricate a SERS substrate denoted as MIL-101-MA@Ag, which can simultaneously produce high-density and uniformly distributed hot spots. Moreover, the enrichment ability of MIL-101(Cr) can further improve the sensitivity by concentrating and transferring the analytes in the vicinity of hot spots. Under optimal conditions, MIL-101-MA@Ag showed good SERS activity for malachite green (MG) and crystal violet (CV), with detection limits as low as 9.5×10-11 M and 9.2×10-12 M at 1616 cm-1, respectively. The prepared substrate has been successfully applied to detect MG and CV in tilapia, the recovery rate of fish tissue extract was 86.4~102%, and the relative standard deviation (RSD) was 8.9~15%. The results demonstrate that MOF-based nanocomposites are expected to be useful SERS substrates and have a universal applicability for the detection of other hazardous molecules.

[Comparative study on pharmacokinetics of senkyunolide I after administration of simple recipe and compound recipe in rats].

OBJECTIVE: To develop a LC-MS method for the determination of senkyunolide I (SI) in rat plasma, in order to observe whether there is significant change in the pharmacokinetics parameters of complex prescriptions of Huoluoxiaolingdan (HLXL) and single herbal extracts from Ligusticum chuanxiong Hort. in rats, and assess the effect of other components in HLXL on the pharmacokinetics of SI. METHOD: Twelve male Sprague-Dawley (SD) rats were randomly divided into two groups, and orally administered with extract from HLXL and L. chuanxiong (both equal to SI 4.53 mg x kg(-1)). Their blood was collected at different time points for LC-MS, in order to detect the plasma concentration of SI. The pharmacokinetic parameters of SI were calculated by DAS 2.0 software. SPSS 16.0 software was used for independent-sample T-test and Nonparametric T-test. RESULT: A linear relationship of SI ranged from 6.750 to 675.0 microg x L(-1), and with the lowest limit of detection being 6.750 microg L(-1). Both of the plasma concentration-time curves of SI were fitted with the two-compartment model for extract of HLXL and L. chuanxiong. The detected AUC and Cmax of SI showed significant difference, with no significant difference in other parameters. CONCLUSION: The LC-MS determination method established in this experiment was so exclusive, accurate and sensitive that it is suitable for pharmacokinetic studies on extracts of HLXL and SI from L. chuanxion. The experiment results show that other ingredients of HLXL have noticeable effect on the absorption of SI in rat plasma.