ABSTRACT
A method for determination of 6 plant growth regulators by high performance liquid chromatography-tandem mass spectrometry ( HPLC-MS/MS ) coupled with isotope-coded derivatization was developed. d0-10-Methyl-acridone-2-sulfonyl piperazine ( d0-MASPz, light form) and d3-10-methyl-acridone-2-sulfonyl piperazine ( d3-MASPz, heavy form ) were prepared as isotope-coded derivatization reagents for carboxyl compound. The carboxyl plant growth regulator standards and real samples were derivatized by d0-MASPz and d3-MASPz, respectively. The obtained solutions were mixed at a certain ratio, and then injected for HPLC-MS/MS analysis. The light and heavy derivatives were monitored with transitions of [M+H]+m/z 208. 2 and [M+H]+ m/z 211. 2,respectively. With heavy derivative as internal standard for corresponding light derivative, the global isotope internal standard quantification for 6 plant growth regulators was achieved. The results indicated that the proposed isotope-coded derivatization method could provide relative quantitative data with adequate linearity in a 10-fold dynamic range ( R=0 . 9991 ) . The detection and quantitation limits were 0. 19-0. 34 μmol/L and 0. 53-0. 96 μmol/L, respectively. The relative standard deviations were ≤3 . 8%, and the accuracies ranged from 97 . 5% to 103 . 8%.
ABSTRACT
With comparison of three different methods for the marking of amines compound, an optimal deri vatization method was selected.5-(2-Hydroxyethyl) benzoacridine (HBA) reacts with coupling agent N,N'-carbonyldiimidazole(CDI) to form an activated amide intermediate 2-(benzoacridin) ethyl-imidazole-1-carbox-ylate(BAEIC).BAEIC, which is dual-sensitive probe, reacts preferably with amino compounds at 80 ℃ in the presence of 4-dimethylaminopyridine(DMAP) catalyst in N,N-dimethylformamide(DMF) solvent to give the corresponding sensitively fluorescent derivatives with an excitation maximum at λ_(ex) of 280 nm and an emis sion maximum at λ_(em) of 510 nm.BAEIC-amine derivatives simultaneously exhibited high ionization potential with percent ionization (changing from 5.62% to 58.08% in aqueous acetonitrile and from 2.14% to 56.58% in aqueous methanol.Derivatives were not only sensitive to fluorescence but also to MS ionizable potential.The fluorescence detection limits(5/iV = 3) were 0.12-0.59 μg/L.The online APCI-MS detection limits were 1.9-14 μg/L(S/N=5).
ABSTRACT
A novel method was established for the qualitative and quantitative determination of fatty acids in Channel Catfish muscle by gas chromatography-electron ionization-mass spectrometry (GC-EI-MS) after supercritical carbon dioxide fluid extraction (SFE-CO_2). The extraction parameters for the methodology were optimized). The optimal conditions were extraction pressure of 25 MPa at 45 ℃ and extraction time of 100 min at the rate of carbon dioxide 30 L/h. The fatty acids in the muscle oil were derived by boron-trifluoride method). The saponification time was 10 min, and the esterication time was 20 min. The obtained fatty acid methylesters were separated by gas chromatography using a HP-Innowax capillary column, and were detected by electron) ionization) mass spectrometry. Full scan mode and SIM mode were used for the qualitative and quantitative analysis), respectively. In the SIM mode, saturated fatty acids were determined with m/z 74, mono-unsaturated) fatty acids were determined with m/z 55, double-unsaturated fatty acids were determined with m/z 67, and polyunsaturated fatty acids were determined with m/z 79. The detection limits of 14 fatty acids were 2.2-20.0 μg/L(S/N=3)), and the quantitative limits were 7.39-59.85 μg/L(S/N=10). The recoveries fell in the range from 90.0% to 111.2%(n=4), and the relative standard deviation was between) 2.0% and 5.9%. This effective, sensitive and reproducible method can be used for the determination of fatty acids in Channel Catfish muscle sample.
ABSTRACT
AIM: To extract and isolate polysaccharide from Poacynum Hendersonii leaves,determine its content and analyze the monosaccharide composition.METHODS: Poacynum Hendersonii leaves was extracted with hot water,crude polysaccharide was precipitated with ethanol,deproteinated according to Sevage method,coloured with acticarbon.Then of polysaccharide contents were measured by anthrone-H_2SO_4 colorimetry at the wavelength of 620 nm.The monosaccharide composition was determined by HPCE.RESULTS: The polysaccharide content was 0.97% of leaf weight,and Gal,Ara,and Man contents were three higher monosaccharides.CONCLUSION : The method is easy to carry out the baseline resolution in HPCE and has highly sensitivity.
ABSTRACT
Objective To study the chemical constituents from the acetone extract in the root of Tibetan medicine Euphorbia wallichii. Methods The constituents were separated by column chromatography with silica gel and purified by Sephadex LH-20. Their structures were identified on the basis of spectral analysis such as IR, HRESIMS, HRSIMS, and 1D-and 2D-NMR techniques ( 1H- 1H COSY , HMQC, HMBC). Results Six compounds were isolated from the acetone extract in the root of E. wallichii. Their structures were identified as lanosterol (Ⅰ), ingenol-20-myristinate (Ⅱ), ingenol-3-myristinate (Ⅲ), acid (Ⅳ), 1-O-?-L-arabinofuranosyl-(1→6)-?-D-glucopyranosyl-3, 7-dimethyl-oct-2-en-7-ol (Ⅴ), 1-O-galloyl-?-D-glucose (Ⅵ) . Conclusion Ingenane diterpene esters ingenol-20-myristinate (Ⅱ) and ingenol-3-myristinate (Ⅲ) are new compounds and other compounds are found from this plant for the first time. It is the first time that monoterpene disaccharide glycoside, compound Ⅴ, is isolated from the plants of Euphorbia L.
ABSTRACT
backbone. The existing form of Ca and P in the skeletons of Sailong and tiger was mainly Ca 10(PO 4) 6(OH) 2. Conclusion The mineral element contents in the skeletons of Sailong and tiger bone have the comparability. It shows that the contents of essential trace elements in Sailong bone are prior to those in tiger bone, significantly.
ABSTRACT
Objective: To explore the preparation process for Tibetan medicine Anshen Pills. Methods: Comparing the preparation process of Tibetan medicine extracted by SFE CO 2 with that extracted by pertroleum ether and analyzing chemical components of their extracts by GC/MS. Results: The method of SFE CO 2 is superior to extractive method by pertroleum ether. The former has higher extraction ratio and shorter extraction time without residues of chemical solvent. Conclusion: The process of SFE CO 2 is suitable for the preparation of Tibetan medicine Anshen Pills.