Rapid Determination of Trace Multiresidues of 18 Sulfonamides in Chicken Eggs Using a Modified QuEChERS Method Coupled with Ultrahigh Performance Liquid Chromatography.

A modified QuEChERS method was used and an ultrahigh performance liquid chromatography (UHPLC) method was developed for the rapid determination of 18 kinds of sulfonamide residues in chicken eggs. Sample preparation and cleanup conditions were carefully evaluated, and factors such as the adsorbent type and adsorption condition were key parameters in improving the cleanup. The modified QuEChERS method removed matrix interferences, and the sensitivity of the method increased about 5% for recovery and efficiency of the method.

Rapid Identification and Quantification of Natural Antioxidants in the Seeds of Rhubarb from Different Habitats in China Using Accelerated Solvent Extraction and HPLC-DAD-ESI-MSn-DPPH Assay.

In this study, the 10 accessions of rhubarb seeds from different habitats in China were investigated. Lipids were removed using petroleum ether, and the effective components were then separated using accelerated solvent extraction with 80% aqueous methanol. An off-line 2,2-diphenyl-1-picrylhydrazyl (DPPH) free-radical scavenging method was used as the marker to evaluate the total antioxidant capability of extracts.

[Simultaneous determination of gastrodin and eight nucleosides and nucleobases in Tibet cultured gastrodia elata by HPLC method].

This study aims to establish an HPLC method for simultaneous determination of gastrodin and eight nucleosides and nucleobases components in Gastrodia elata. The separation was carried out on an Agilent Zorbax Bonus-RP (4.6 mm x 250 mm, 5 μm) column with a methanol-(0.

Spatial variation profiling of four phytochemical constituents in Gentiana straminea (Gentianaceae).

Gentiana straminea is the famous Tibetan folk medicine thought to cure various diseases. Historically, the Qinghai-Tibetan region has been considered as the geo-authentic production area of "Mahua Jiao," where large quantities of the medicine are grown. However, there is still little known about the phytochemical constituent spatial variation of this species.

[Determination of trace element contents in Urtica laetevirens Maxim. reaped in different months by ICP-MS].

The contents of twenty kinds of trace elements, Al, Ba, Ca, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, S and Zn, were determined by ICP-MS with microwave digestion in Urtica laetevirens Maxim. The recovery (n=7) is 95.4%-101.

Study on mineral elements in Salvia roborwskii from the Qinghai-Tibet Plateau.

The contents of trace elements, including aluminum, barium, beryllium, calcium, cobaltium, chromium, copper, iron, potassium, lanthanum, lithium, magnesium, manganese, sodium, nickel, phosphorus, lead, sulfur, silicon, titanium, vanadium, and zinc, were determined by ICP-AES. The mean concentrations of the 22 elements were as follows: K>Ca>Mg>Fe>Al>Na>S>P>Ba>Ti>Mn>Zn>Sr>Cu>Ni=Cr>Pb>V>Li=La>Co>Be. Principal components analysis of SPSS was applied to study the characteristic elements in Salvia roborwskii.

[Determination of trace determination of elements in medicinal materials of cultivated and wild Rhizoma et Radix Notopterygii vegetated in different months by flame atomic absorption spectrometry].

The contents of six trace elements Ca, Mg, Fe, Mn, Cu and Zn in the medicinal materials of cultivated and wild Rhizoma et Radix Notopterygii vegetated in different months were determined by flame atomic absorption spectrometry (FAAS) with air-acetylene flame, and the feature of trace elements contents and their seasonal dynamics were analyzed using SPSS16.0 analysis software. The recovery rate obtained by standard addition method ranged between 96.

[Analysis of total alkaloids in Meconopsis quintuplinervia from different localtites of Qinghai].

The contents of total alkaloids in Meconopsis quintuplinervia Regel, grown in the different localtites of Qinghai Province, are detected by the method of spectrophometry. The result showed that total alkaloid in different localities were 0. 0262% to approximately 0.

[Determination of papaverine in seeds of Papaver somniferum L. and soup of chafing dish by high performance liquid chromatography-fluorescence detection].

A method of reversed-phase high performance liquid chromatography coupled with fluorescence detection was developed for the separation and determination of papaverine in seeds of Papaver somniferum L. and soup of chafing dish. The liquid chromatographic experiment was carried out under the following conditions: the detector was a fluorescence with excitation wavelength at 285 nm and emission wavelength at 355 nm.

[Content determination of loganic acid and gentiopicroside in Tebitan herbal medicines Gentiana macrophylla and G. straminea by HPLC].

A quantitative method to determine loganic acid and gentiopicroside in Gentiana macrophylla Pall. and Gentiana straminea Maxim. by RP-HPLC was established in this paper.

[Determination of xanthones in Swertia mussotii and Swertia franchetiana by high performance liquid chromatography].

A simple and rapid method for simultaneous separation and determination of xanthones in Swertia mussotii and Swertia franchetiana by high performance liquid chromatography has been established. The analysis was performed on a Kromasil C18 column (250 mm x 4.60 mm i.

[Determination of the base contents of liver DNA of rats by reversed-phase high performance liquid chromatography].

The base contents of liver deoxyribonucleic acid (DNA) of rats living at an altitude of 2.3 km were determined by reversed-phase high performance liquid chromatography. At first, 0.