Simultaneous determination of sex hormones in egg products by ZnCl2 depositing lipid, solid-phase extraction and ultra performance liquid chromatography/electrospray ionization tandem mass spectrometry.

A method was developed for simultaneous determination of residues of 17 sex hormones in egg products. Target compounds were extracted from samples with methanol in an ultrasonic bath, effectively separated from lipids in the extracts by ZnCl(2) depositing filtration and purified using a C(18) solid-phase extraction (SPE) and followed by NH(2) SPE cartridge. The analytes were quantified by liquid chromatography using a BEH C(18) column coupled to an electrospray ionization tandem mass spectrometer (LC-ESI-MS/MS) operating in negative mode for estrogens and in positive multiple reaction monitoring mode for androgens. The parameters of the mass spectrometer and the composition of mobile phase and additives were also optimized to enhance detection sensitivity. Average recoveries of the target compounds varied from 70.0% to 121.0% with relative standard deviations ranging from 2.3% to 11.2% at two fortification levels. The limits of detection (LOD) of the method were from 0.002 µg kg(-1) to 0.23 µg kg(-1) and the limits of quantification (LOQ) were in the range of 0.007-0.76 µg kg(-1).

Titanium-coated silica spheres prepared by self-assembly technique for use as HPLC packing.

Titania-coated silica spheres were prepared by a layer-by-layer self-assembly technique for use as a high-performance liquid chromatography packing. This packing has a high surface area of 202.1 m(2)/g, a large pore volume of 0.36 cm(3)/g, and a pore diameter of 7.0 nm. Furthermore, the packing particles exhibit narrow pore size distribution and good pore structure. The chromatographic behavior of the packing was studied under both normal and reversed-phase conditions. Low column pressures were observed. Aromatic isomeric compounds were well separated on the TiO(2)/SiO(2) column under normal phase conditions; pyridine and aniline derivatives were separated on the octadecyl-bonded TiO(2)/SiO(2) (ODT) column, respectively, under reversed-phase conditions, and highly symmetrical peaks were obtained for 15 basic compounds. The chemical stability of the stationary phase was tested with sodium phosphate solution (10 mmol/L, pH = 10) at 25 degrees C and potassium phosphate solution (50 mmol/L, pH = 10) at 50 degrees C.

[HPLC fingerprinting of total glycosides of Swertia franchetiana].

AIM: To establish a sensitive and specific HPLC method for controlling the quality of total glycosides from Swertia franchetiana H. Smith. METHODS: HPLC method was applied for quality and quantitative assessment of the pharmaceutical extracts from Swertia franchetiana H. Smith. The preparation of sample, the HPLC column, mobile phase, elution mode (isocratic or gradient) and gradient program were optimized in order to obtain HPLC profile. The HPLC system consisted of a SPD-1OAvp pump, SPD-M1OAVP photodiode-array detector (PAD), SIL-10ADVP auto injector. Data were acquired and processed with the CLASS-VP6.1 workstation. HPLC analysis was performed on a Kromasil C18 column (250 mm x 4. 6 mm ID, 5 microm) with methanol and water as mobile phase. The column temperature was set up at 40 degrees C and the flow-rate was 1 mL x min(-1). The reference solution of chemical standards and sample were injected into HPLC system, separately. RESULTS: The HPLC chromatographic fingerprinting of the total glycosides, showing 16 characteristic peaks which were partitioned into three parts: one peak in 0-10 min of retention time, nine peaks containing main 1-7 peaks in 10-15 min of retention time, 6 peaks in 15-30 min of retention time, was established from 10 lots of their products. By comparison of the retention time and the on-line UV spectra and their molecule weights of chemical standards, peak 1-7 were identified as swertiamarin (1), gentiopicroside (2), sweroside (3), isoorientin (4), swertisin (5), isoswertisin (6) and swetianolin (7), respectively. The ratios of peak area between 1-16 were in their extent. Moreover, comparison of the HPLC profiles of the total glycosides, the extracts prepared using another process and the plant indicated that they were closely related to each other. CONCLUSION: The HPLC profiles and quantitative assessment of the total glycosides from Swertia franchetiana H. Smith with high specificity can be used to control their quality and assure lot to lot consistency.

Normal-phase HPLC enantioseparation of novel chiral metal tetrahedrane-type clusters on an amylose-based chiral stationary phase.

In the present work, an amylose tris(3,5-dimethylphenylcarbamate) (ADMPC) chiral stationary phase (CSP) was prepared by coating ADMPC on small-particle silica gel. This ADMPC-CSP was for the first time successfully applied to separate a series of novel chiral metal tetrahedrane-type clusters. Furthermore, the influence of a mobile-phase modifier (various alcohols added in the mobile phase), including its concentration and structure, and the structures of the clusters on the chiral separation and retention was investigated. The results suggest that not only the structure and concentration of alcohol in the mobile phase, but also the subtle structural differences in racemate can have a pronounced effect on the enantiomeric separation and retention.

Preparation and evaluation of non-bonded hyperbranched polymer-coated columns for capillary electrophoresis.

A series of hyperbranched poly(amine-ester)s based on 1,1,1-trimethylolpropane, methyl acrylate and diethanolamine were synthesized and coated on the inner surface of the fused-silica capillaries by physical adsorption. The most effective coating was the seventh generation hyperbranched poly(amine-ester) coating, which reduced the electroosmotic flow (EOF) greatly and suppressed protein adsorption effectively. The high separation efficiencies for basic proteins were obtained and the coating had a good stability.

Separation of cefoperazone enantiomers using beta-cyclodextrin as chiral additive by capillary zone electrophoresis.

A capillary electrophoresis method was developed to separate the enantiomers of cefoperazone. Different cyclodextrins, including alpha-cyclodextrin (alpha-CD), beta-cyclodextrin (beta-CD), gamma-cyclodextrin (gamma-CD), 2-hydroxypropyl-beta-cyclodextrin (HP-beta-CD), and methyl-beta-cyclodextrin (Me-beta-CD), were tested as chiral additives in the running buffer. The effect of various parameters on enantioseparation such as concentration of NaH(2)PO(4), buffer pH, and CD concentration was also studied. The cefoperazone enantiomers were baseline separated under conditions of 0.04 mmol/L beta-CD, 75 mmol/L NaH(2)PO(4) buffer at pH 4.0. A fused silica capillary (40 cm effective length x 75 microm ID) was used. The applied voltage and capillary temperature were 20 kV and 25 degrees C, respectively. Under these conditions, linear calibration curves were obtained in the 5-500 microg/ml range using UV detection at 280 nm. The limit of detection for both isomers was 0.1 microg/ml. The method was used for the analysis of different pharmaceutical preparations (dose) and biological samples containing cefoperazone.

Determination of serum thyroxine enantiomers in patients by liquid chromatography with a chiral mobile phase.

A chromatographic method for the separation and determination of D- and L-thyroxine enantiomers (D-, and L-T4) in human serum with a chiral ligand ion-exchange system using a chiral mobile phase additive and a silica column was established. An aqueous eluent containing L-proline (L-pro) sufficiently complexed copper II ions and triethylamine (TEA) was used. It was monitored with a UV detector. The separation was completed in 12 min. The method has acceptable sensitivity, precision and accuracy for analysis. The limit of detection and the limit of quantitation for both D- and L-T4 were 0.1 microg/ml and 0.8 microg/ml, respectively. Calibration curves were linear within 1-100 microg/ml; the mean correlation coefficients were r(D-T4)=0.9986 for D-T4 and r(L-T4)=0.9978 for L-T4. T4 enantiomers were separated on baseline under the optimum condition. L-T4 eluted before D-T4. The concentration of D-T4 and L-T4 in 45 thyroid patients serum (hyperthyroid, hypothyroid, thyroidectomy, goitre or thyroiditis) using HPLC was determined, those results showed that D,L-T4 concentration varied in different thyroid patient. Attention should be paid to this result in treating thyroid disease in the clinic.

[Determination of alkaloids from Coptis chinensis Franch. and Phellodendron amurense Rupr. Decocted together in baitouweng decocta by high performance capillary electrophoresis].

A rapid and accurate method for determining alkaloids from Coptis chinensis Franch, and Phellodendron amurense Rupr, decocted together in Baitouweng decocta was established. Experiments were carried out on a self-assembled capillary electrophoresis system. The experimental conditions were as follows: 75 microns i.d. x 50 cm fused silica capillary, 0.05 mol/L Na2B4O7-CH3OH (85:15, V/V) as buffer, applied voltage 14 kV and detection wavelength 232 nm. In addition, the concentration of ethanol in the extraction solvent was optimized. Experimental results showed that ethanol-water (30:70, V/V) was the ideal solvent to extract the main effective ingredients from Coptis chinensis Franch. and Phellodendron amurense Rupr. decocted together in Baitouweng decocta. Berberine and palmatine had good linearities in the range of 15.0 mg/L-65.0 mg/L and 12.5 mg/L-50.0 mg/L respectively, and their average recoveries were 95.5%-104% (RSD 2.7%-6.9%) and 92.1%-103% (RSD 4.5%-6.7%) respectively.

[Studies of aroma components on essential oil of Chinese kushui rose].

The main chemical components of the rich peculiar aroma in the essential oil of Chinese Kushui rose (R. Setate x R. Rugosa) is reported. The differences in chemical components between Chinese Kushui rose oil and Bulgaria rose oil are compared. By OV1701 capillary column, more than 130 compounds were separated from the essential oil of Chinese Kushui rose. Using GC/MS and GC/IR techniques and some reference standards as the control, 101 compounds were tentatively identified from the separated compounds. This study shows that there are different aromas in rose essential oils. The oil of Chinese Kushui rose would be an important type of rose oil in the world due to its special rose aroma.

[Effect of the bonding amounts of chiral ligand exchange chromatographic stationary phases on the enantioseparation of amino acids].

L-proline chiral stationary phases with various bonding amounts for ligand exchange chromatography were prepared by treating silica gel with 3-glycidoxypropyltrimethoxysilane and bonding L-proline. The bonding amounts of L-proline chiral stationary phase were controlled effectively and characterized by IR and elemental analysis. Some DL-amino acids were separated and the influences of the bonding amounts on the efficiency of resolution of DL-amino acids by ligand exchange chromatography were briefly discussed and explained by the mechanism of the separation.

[Influence of mobile phase composition on chiral separation of organic selenium racemates].

The chiral separation of some chiral compounds with similar structure on the cellulose tris (3,5-dimethylphenylcarbamate) chiral stationary phase prepared by us was obtained. Ternary mobile phases influencing chiral recognition were investigated. A mode of interaction between the structural character of samples and chiral stationary phase is discussed. The results indicated that the retention and chiral separation of the analytes had a bigger change with minute addition of alcohols or acetonitrile as modifier in n-hexane/2-propanol (80/20, volume ratio) binary mobile phase.