ABSTRACT
A method has been developed by solid phase extraction-high performance liquid chromatography coupled with photodiode array detector for simultaneous determination of 10 kinds of cyanotoxins in lake water, including microcystin-RR (MC-RR), MC-YR, MC-HtyR, MC-LR, MC-WR, MC-LA, MC-LY, MC-LW, MC-LF and nodularin ( NOD ).The samples were enriched and purified by a HLB solid phase extraction column.The separation was performed on a Waters C18 column (250 mm×4.6 mm, 5 μm) with the gradient elution of acetonitrile and water containing 0.05% trifluoroacetic acid.The flow rate of the mobile phase was 0.8 mL/min.The column temperature was 30℃ and the injection volume was 20 μL.The photodiode array detector was scanned from 190 nm to 300 nm and the detection wavelength was 238 nm.Multiple qualitative analyses were completed according to retention time, full scanning spectrum of photodiode array detector and purity analysis of chromatographic peak.Good linearity was observed in the cyanotoxin concentration range of 0.05 mg/L-2.0 mg/L with correlation coefficients ( R) from 0.9998 to 0.9999.The limits of detection for 10 cyanotoxins were in the range of 0.005 μg/L-0.020 μg/L.The recoveries were in the range of 85.1%-105.3% at the three spiked levels of 0.1 mg/L, 1.0 mg/L and 1.8 mg/L with the relative standard deviations ( RSD ) of 0.8% -9.2%.The method was characteriZed by wide applicability, convenient operation, quick analytical rate, high sensitivity, good accuracy and high recovery.The qualitative accuracy was improved by using multiple qualitative analyses.This method was successfully applied to determination of 10 kinds of cyanotoxins in lake water.
ABSTRACT
Aim: To investigate the chemical components in Zhizidahuang decoction( ZZDHD) to reveal the possible material therapeutic basis. Methods: High performance liquid chromatography coupled with photodiode array detector and tandem mass spectrometry ( HPLC-PDA-MS/MS) was applied to simultaneously characterize the chemical components and their structures in ZZDHD. The analysis was preformed on a Lichrospher C_(18) column using a binary eluent of 0. 1% acetic acid( A) and methanol( B) mixed under the gradient mode; UV spectra were scaned from 210 nm to 480 nm; negative ESI experiments in data-dependent scan mode were performed. Results: HPLC-PDA-MS/MS chromatogram of ZZDHD was achieved. Based on UV spectral data, information of molecular weight and mass fragmentation behaviors connected with extracted ion current( EIC) chromatogram, twenty kinds of components were detected and identified, including flavonoids, anthraquinones, iridoids and other constituents. Conclusion: The method presented in this study, which combined HPLC with UV and MS, allowes the characterization of compounds in the complex herbal system even without the reference standards.