On-line cleavage of urinary estriol conjugates with immobilized beta-glucuronidase before liquid-chromatographic analysis.

1981 ◽  
Vol 27 (9) ◽  
pp. 1554-1557 ◽  
Author(s):  
L D Bowers ◽  
P R Johnson
Keyword(s):  
High Performance ◽  
Immobilized Enzyme ◽  
Gradient Elution ◽  
Storage Conditions ◽  
Reversed Phase ◽  
Liquid Chromatograph ◽  
On Line ◽  
Liquid Chromatographic Analysis ◽  
The Stability ◽  
Liquid Chromatographic

Abstract Urinary estriol measurement has been widely accepted as a useful indicator of fetoplacental status. Classically, glucuronide conjugates of estriol have been cleaved with soluble beta-glucuronidase (EC 3.2.1.31) before extraction and measurement. We have developed a system in which urine is injected directly into a "high-performance" liquid chromatograph and the conjugates are cleaved on-line in an immobilized beta-glucuronidase reactor. Estriol is quantitated with fluorescence detection after separation from other interfering species with a reversed-phase column. The stability of the immobilized enzyme under storage conditions and in the presence of the mobile phase are discussed. Only 150 mL/L methanol could be pumped through the reactor and onto the analytical column, but this allowed on-column preconcentration of the free estriol produced. Gradient elution bypassing the immobilized enzyme reactor eluted the compounds of interest without damaging the enzyme. Comparison with radioimmunoassay results yielded a slope of 0.97 (r = 0.996, n = 19).

On-line direct liquid introduction interface for micro-liquid chromatography/mass spectrometry: application to drug analysis.

1982 ◽  
Vol 28 (9) ◽  
pp. 1882-1886 ◽  
Author(s):  
C Eckers ◽  
D S Skrabalak ◽  
J Henion
Keyword(s):  
Mass Spectrometer ◽  
High Performance ◽  
Biological Fluids ◽  
High Performance Liquid Chromatographic ◽  
Drug Analysis ◽  
Liquid Chromatograph ◽  
Mass Spectral ◽  
On Line ◽  
The Stability ◽  
Liquid Chromatographic

Abstract We describe an integrated micro-liquid chromatograph/mass spectrometer (micro-LC/MS) system capable of performing routine determinations for 1--10 ng of drugs and their metabolites extracted from biological fluids. The micro-LC is constructed from conventional "high-performance" liquid-chromatographic instrumentation by using commercially available components. The mass spectrometer is operated in the chemical ionization mode. The direct liquid introduction micro-LC/MS interface can be constructed from commercially available materials. Chromatographic and mass spectral results demonstrate the ability of the micro-LC and micro-LC/MS system to separate and determine multiple components in standards of trace concentrations and in equine urinary extracts. The stability and sensitivity of this micro-LC/MS system are demonstrated through determinations of trichlormethiazide.

Reversed-Phase High Performance Liquid Chromatographic Analysis of Three First Line Anti-Tuberculosis Drugs

2019 ◽  
Vol 69 (12) ◽  
pp. 3590-3592
Author(s):  
Nela Bibire ◽  
Romeo Iulian Olariu ◽  
Luminita Agoroaei ◽  
Madalina Vieriu ◽  
Alina Diana Panainte ◽  
...  
Keyword(s):  
High Performance ◽  
Biological Fluids ◽  
Gradient Elution ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Assay Method ◽  
Active Pharmaceutical Ingredients ◽  
First Line ◽  
Pharmaceutical Ingredients ◽  
Liquid Chromatographic

Active pharmaceutical ingredients such as isoniazid, pyrazinamide and rifampicin are among the most important first-line anti-tuberculosis drugs. A simple, rapid and sensitive reversed phase-high performance liquid chromatographic assay method for the simultaneous determination of isoniazid, pyrazinamide and rifampicin has been developed. Separation of the interest compounds was achieved in a 10 min chromatographic run in gradient elution mode on a Zorbax SB-C18 stainless steel column (150 � 4 mm, 5 mm) using a guard column containing the same stationary phase. The gradient elution was carried out with a mobile phase of 10% CH3CN aqueous solution for channel A and 50% CH3CN in pH = 6.8 phosphate buffer (20 mM), to which 1.5 mL triethylamine were added for channel B. Quantification of the analyzed substances was carried out spectrophotometrically at 269 nm. Detection limits of 0.48 mg/L for isoniazid, 0.52 mg/L for pyrazinamide and 0.48 mg/L for rifampicin were established for the developed assay method. The present work showed that the proposed analysis method was advantageous for simple and rapid analysis of the active pharmaceutical ingredients in pharmaceuticals and biological fluids.

scholarly journals CHEMICAL STUDY OF FLAVONS AND FLAVONOLS COMPOSITION IN PROPOLIS

2018 ◽  
Vol 6 (3) ◽  
pp. 241-254
Author(s):  
E. V. Lupina ◽  
D. I. Pisarev ◽  
O. O. Novikov ◽  
A. Yu. Malyutina ◽  
G. V. Vasilev ◽  
...  
Keyword(s):  
High Performance ◽  
Chemical Study ◽  
Gradient Elution ◽  
Reversed Phase ◽  
Array Detector ◽  
Absolute Calibration ◽  
Diode Array Detector ◽  
Liquid Chromatograph ◽  
Quantitative Content ◽  
Traditional Scheme

The aim of the study. This article is dedicated to the comparative assessment of flavones and flavonols composition in various samples of propolis for providing the possibility of its standardization. Materials and methods. To carry out the research, 6 experimental samples of propolis were taken from different regions of Russia. Using those samples, we prepared the extracts with 80% ethanol according to traditional scheme of making tinctures in the ratio of 1:10. After that our extracts were filtered and used directly in the assessment. Chromatographic separation of spirit extracts of propolis was carried out on a liquid chromatograph of “Agilent Technologies 1200 Infinity”, USA. The detection was carried out on the basis of the diode array detector “Agilent 1200”. Results and discussion. Using the reversed-phase HPLC in gradient elution regime we managed to identify flavonols and flavones. It was found out that the composition of propolis has a stable composition of flavones and flavonols including quercetin, isoramnetin, 3,4’-dimethoxycempferol, ramnetin, penduletin, kaempferol, ramnocitrin, galangin, kaempherid, chrysin and methoxyhalangin. Among the identified components, the highest content is in flavonols, methoxyl derivatives ramnocitrin (22,0%), and kaempherid (12,0%); in flavones it is chrysin(16,0%). The specific gravity of each component within the specified group was calculated by the internal normalization method. It was established that about 84% of all flavonols are in kaempferol and its methoxyl derivatives. The composition of flavones and flavonols can vary depending on the sample. Hereby, kempferol was identified in all the studied samples, whereas some of the identified components were absent from separate propolis samples. Propolis standardization by method of high-performance liquid chromatography in respect of the content of flavonoids in terms of kaempferol as a stable, commercially most available component of propolis was suggested. With the use of absolute calibration, the quantitative content of kaempferol in propolis samples wasdetermined in the range of 0.0141-0.0159%. Conclusion. The results of the carried out experiments made it possible to recommend the quality assessment of propolis according to the content of kaempferol in the experimental samples.

Application of "high-performance" liquid chromatography to the study of sphingolipidoses.

1980 ◽  
Vol 26 (10) ◽  
pp. 1499-1503 ◽  
Author(s):  
M D Ullman ◽  
R E Pyeritz ◽  
H W Moser ◽  
D A Wenger ◽  
E H Kolodny
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Plasma Exchange ◽  
Chromatographic Analysis ◽  
High Performance ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Urine Sediment ◽  
Liquid Chromatographic Analysis ◽  
Liquid Chromatographic

Abstract Quantitative high-performance liquid chromatographic analysis of perbenzoylated sphingolipids has been used to study the correlations of body chemistry to clinical phenomena. Plasma sphingolipids were isolated from 32 Gaucher (β-glucosidase deficiency) and six Fabry (α-galactosidase deficiency) patients by solvent partition and chromatographic separation on silicic acid columns. Plasma sphingolipids from a patient undergoing plasma-exchange were separated from interfering lipids with reversed-phase columns. Liquid-chromatographic analysis of sphingolipids provides useful supportive information for diagnoses because affected individuals are shown to possess increased circulating concentrations of the pathognomonic sphingolipid. We also used this technique to monitor sphingolipid concentrations in plasma and urine sediment during plasma exchange of a p atient with Fabry’s disease. Regular plasma exchanges produced and maintained decreased concentrations of sphingolipids in plasma, but near pre-exchange concentrations were observed within days after the therapy was terminated.

On-line liquid-chromatographic analysis for drugs in serum with the Technicon "FAST-LC" system: performance data for theophylline and for four commonly used anticonvulsants and their metabolites.

1980 ◽  
Vol 26 (7) ◽  
pp. 871-880 ◽  
Author(s):  
J W Dolan ◽  
S van der Wal ◽  
S J Bannister ◽  
L R Snyder
Keyword(s):  
High Performance ◽  
Total Sample ◽  
Sample Volume ◽  
Active Metabolites ◽  
Serum Samples ◽  
New Instrument ◽  
On Line ◽  
Liquid Chromatographic Analysis ◽  
Liquid Chromatographic ◽  
Total Sample Volume

Abstract We describe a new instrument for use in assay of therpeutic drugs in serum by "high-performance" liquid chromatography, the "FAST-LC" system (Technicon). Serum samples are aspirated directly into the unit, extracted with solvent, and the evaporated and redissolved extract is injected onto a chromatographic column. We illustrate the performance of the system by assays in serum for theophylline and four anticonvulsants (primidone, phenobarbital, phenytoin, and carbamazepine) plus two of their active metabolites (phenylethylmalonamide and carbamazepine epoxide). For theophylline, final chromatograms are monitored at 270 nm, at analysis rates of 10/h. Concentration and absorbance are linearly related from 0 to 130 mg of theophylline per liter. For the anticonvulsants, chromatograms are monitored at 200 nm, at analysis rates of 7.5/h. The six individual determinations are each linear beyond the therapeutic range. For both drug panels, day-to-day CV's were 4 to 6%. Results correlate well with those by enzyme immunoassay. A total sample volume of 150 microL is required.

scholarly journals Constituents of Da-Cheng-Qi Decoction and its Parent Herbal Medicines Determined by LC-MS/MS

2010 ◽  
Vol 5 (5) ◽  
pp. 1934578X1000500
Author(s):  
Fengguo Xu ◽  
Ying Liu ◽  
Rui Song ◽  
Haijuan Dong ◽  
Zunjian Zhang
Keyword(s):  
High Performance ◽  
Herbal Medicines ◽  
Gradient Elution ◽  
High Performance Liquid Chromatographic ◽  
Reversed Phase ◽  
Esi Ms ◽  
Chemical Constitution ◽  
Tandem Mass Spectrometric ◽  
Liquid Chromatographic ◽  
First Time

Da-Cheng-Qi decoction (DCQD) is a purgative prescription used in China and East Asia. To profile the constituents of this complex traditional Chinese medicine (TCM), a high-performance liquid chromatographic, electrospray ionization, tandem mass spectrometric (HPLC-ESI/MS/MS) analytical method was developed. After separation on a reversed-phase C18 analytical column using gradient elution, samples were analyzed by ESI-MS/MS in negative mode. As a result, a total of 37 compounds were detected, of which two tannins, three anthraquinones, two sennosides, five flavonoids and two lignans were unambiguously identified by comparison with standard compounds, and sixteen compounds were either tentatively identified or deduced according to their MS/MS data. The fragmentation pathways of many of the observed compounds, such as the tannins and lignans are reported for the first time. In addition, the identity of each peak in DCQD was explored by comparison with those of its three constituent herbs. The results indicated that tannins, anthraquinones and sennosides in DCQD originated from Radix et Rhizoma Rhei, flavonoids from Fructus Aurantii Immaturus, and lignans from Cortex Magnoliae officinalis. The present study provides an example of chemical constitution profiling in complex TCM systems using LC/MS/MS.

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