The following article references are intended to highlight published applications articles using Pickering Laboratories instruments and chemicals. The title, author, publication and abstract are included to assist in the acquisition of the entire articles from Linda Hall Library of Science, Engineering and Technology, http://www.lindahall.org Pickering Laboratories is not the publisher of these articles and cannot provide them to the interested parties.
| AMOXYCILLIN | BROMATE | CATACHOLAMINES | Cr+6/ AIR & H2O |
| CARBOHYDRATE | LC- MS |
AMOXYCILLIN Journal of Chromatography, 344 (1985) 285-296
Biomedical Applications
Elsevier Science Publishers B.V., Amsterdam- Printed in The Netherlands CHROMBIO. 2718 AUTOMATED DETERMINATION OF AMOXYCILLIN IN BIOLOGICAL FLUIDS BY COLUMN SWITCHING IN ION-PAIR REVERSED-PHASE LIQUID CHROMATOGRAPHIC SYSTEMS WITH POST-COLUMN DERIVATIZATION
Jan Carlqvist and Douglas Westerlund*
Department of Bioanalytical Chemistry, Research and Development Laboratories, Astra Lakemedel AB, S-151 85 Sodertalje (Sweden)
Summary Amoxycillin, a polar aminopenicillin, is rather unstable in biological fluids. Degradation can be prevented by fast sample pretreatment and storage at -70° C or below. After pH adjustment, it is stable in biological fluids for over
16 h. The samples were handled by automated chromatography overnight. The chromatographic system consisted of a small guard column, two analytical columns separated by a switching valve, a post-column reactor and a fluorescence detector. The chromatographic events and the calculation of results were handled by a computing integrator.
The chromatography was based on ion-pairing principles. An efficient clean-up of the biological fluids was obtained by a heart cut from the first column, where the neutral phase contained hexyl sulphate. In the second column the organic anion was exchanged for a large quaternary ammonium compound; amoxycillin was then retained as an ion pair. The composition of the mobile phases had to be designed carefully in order to avoid a disturbance of the chromatographic performance on the last column. An adequate selectivity and sensitivity was obtained by a post-column derivatization with fluorescamine.
Detection limits were 10 and 25 ng/ml for plasma and urine, respectively, and the interassay precisions at low levels (350 and 2000 ng/ml for plasma and urine, respectively) were ca. 5% (R.S.D.).
Journal of Chromatography, 506 (1990) 417-421
Elsevier Science Publishers B.V., Amsterdam- Printed in The Netherlands
CHROMSYMP. 1689 DETERMINATION OF AMOXICILLIN IN PLASMA BY HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY WITH FLUORESCENCE DETECTION AFTER ONLINE OXIDATION
H. Mascher* and C. Kikuta
Pharm-Analyt Lab. GmbH, Wienerstrasse 37, P.O. Box 4, A-2514 Traiskirchen/Vienna (Austria) Summary A simplified high-performance liquid chromatographic method for the determination of amoxicillin in plasma is described. Specific and sensitive fluorescence detection was achieved by on-line post-column electrochemical oxidation, using an electrochemical detector. Owing to the high specificity of the detection system, deproteinized plasma samples could be injected directly without prior treatment. This method permits fast and reproducible determination of amoxicillin in plasma on a routine basis at levels, down to 50 ng/ml. The absolute detection limit is about 10 pg injected.
ANG ET AL.:Journal of AOAC International Vol. 79, No. 2, 1996
DETERMINATION OF AMOXICILLIN IN CATFISH AND SALMON TISSUES BY LIQUID CHROMATOGRAPHY WITH PRECOLUMN FORMALDEHYDE DERIVATIZATION
Catharina Y.W. ANG, Wenhong Luo, Eugene B. Hansen, JR, James P. Freeman, and Harold C. Thompson, JR
U.S. Food and Drug Administration, National Center for Toxicological Research, Division of Chemistry, 3900 NCTR Rd, Jefferson, AR 72079-9502
Summary A liquid chromatographic (LC) method with fluorescence detection was developed for analysis of amoxicillin in catfish and salmon tissues. The tissue was extracted with phosphate buffer (pH 4.5), followed by trichloroacetic acid (TCA) precipitation of proteins and solid-phase (C18) extraction. Trace amounts of nonpolar interfering substances present after solid-phase extraction. The extract was reacted with formaldehyde and TCA at 100°C for 30 min. A fluorescent derivative was extracted with ether, concentrated, and analyzed by reversed-phase LC with fluorescence detection. Average recoveries of amoxicillin spiked at 2.5-20 ppb were >80% for catfish and >75% for salmon muscle tissue, with coefficients of variation of <6%. Limits of detection (LOD) and quantitation (LOQ) for catfish tissue were 0.5 and 1.2 ppb, respectively. LOD and LOQ for salmon muscle tissue were 0.8 and 2.0 ppb, respectively.
BROMATE Food Additives and Contaminants, 1996, Vol. 13, No. 6, 633-638
MEASUREMENT OF BROMATE IN BOTTLED WATER BY HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY WITH POST-COLUMN FLOW REACTOR DETECTION
Charles R. Warner, Daniel H, Daniels, Frank L. Joe, JR and Gregory W. Diachenko
Office of Premarket Approval, US Food and Drug Administration, 200 C Street, SW, Washington DC 20204, USA
Summary The objective of this work was to develop a reliable, rugged high-performance liquid chromatographic (HPLC) method for determination of trace levels of bromate (<10 ?g/1) in bottled water. HPLC separation was achieved by ion interaction chromatography using a C-18 reversed-phase column and a mobile phase consisting of methanol/water (20:80, v/v) with tetrabutylammonium acetate as the ion interaction reagent. A post-column reaction based on oxidation of o-dianisidine in acidic solution to a product detected at 500 nm provided selective measurement of the oxidants. The limit of detection and the limit of quantitation were 1 and 3 ?g/1, respectively. Iodate, chlorite, and nitrite were chromatographically separated from bromate and measured by monitoring the post-column reaction. Chloride and chlorate at levels that might be found in bottled water did not interfere with the determination of bromate. Bromate was detected in bottled waters at concentrations up to 40 ?g/1. Keywords: bottled water, bromate, chlorite, iodate, ion interaction chromatography
CATACHOLAMINES Analytica Chimica Acta, 97 (1978) 357-363
Elsevier Scientific Publishing Company, Amsterdam- Printed in The Netherlands AN H.P.L.C- FLUORIMETRIC ANALYSIS FOR L-DOPA, NORADRENALIN AND DOPAMINE
Peter M. Froehlich* and Thomas D. Cunningham**
Trace Analysis Research Center, Department of Chemistry, Dalhousie University, Halifax, N.S. B3H 4J3 (Canada)
Summary A rapid (10 min) and sensitive determination of 3, 4-dihydroxyphenyl-L-alanine (L-dopa), noradrenalin and dopamine has been developed. The assay involves the separation of the compounds with a strong cation-exchange resin, followed by post-column derivatization with o-phthalaldehyde. The fluorescence of the derivative is measured in a flow-through fluorimeter and is linear over a concentration range of 500 times the lower detection limit (4.6 ng for L-dopa, 7.5 ng for noraddrenalin, and 9.3 ng for dopamine). The assay does not require the stringent removal of oxidizing materials which is necessary for electrochemical detection, and may be useful in the analysis of biological samples.
Cr+6/ AIR & H2O Anal. Chem. 1999, 71, 4203-4207 OPTIMIZATION OF THE SIMULTANEOUS DETERMINATION OF Cr (III) AND Cr (VI) BY ION CHROMATOGRAPHY WITH CHEMILUMINESCENCE DETECTION
Michelle Deryshire* and Andree Lamberty
European Commission Joint Research Center (JRC), Institute for Reference Materials (IRMM), Retieseweg, B-2440 Geel, Belgium
Philip H. E. Gardiner*
Division of Chemistry, School of Science and Mathematics, Sheffield Hallam University, Howard Street, Sheffield, S1 1WB, UK Summary An optimized method for the simultaneous determination of Cr (III) and Cr (VI) in aqueous solutions using ion chromatography with chemiluminescence detection is described. Excellent resolution of the two chromium species was obtained using a single mixed-bed ion exchange column with continuous elution. After post-column reduction of Cr (VI) to Cr (III), the light emitted during the Cr (III)-catalyzed oxidation of luminol with hydrogen peroxide was measured. Parameters affecting the post-column reactions such as reductant concentration, reductant mixing, point of luminol introduction, and luminol flow rate were optimized. The calibration curves in the range tested (0.01-50 ?g/L-1) were linear, and detection limits of 0.002 ?g/L-1 for both Cr (III) and Cr (VI) were obtained. The results of the analyses of the water reference materials LGC CRM6010 and NIST SRM1643d with certified chromium valves of 49 + 4 and 18.53 + 0.20
?g/L-1 and found to contain only Cr(III) were 49.2 + 1.8 and 19.0 + 1.5 ?g/L-1, respectively. Values of 10.6 + 0.5 and 10.1 + 0.5 u?g/L-1 were obtained when a simulated water sample containing 10 u?gL-1 Cr (III) and Cr (VI) was analyzed.
CARBOHYDRATE Journal of Chromatography A, 720 (1996) 183-199 POSTCOLUMN DERIVATIZATION FOR CHROMATOGRAPHIC ANALYSIS OF CARBOHYDRATES
Faculty of Pharmaceutical Sciences, Kinki University, 3-4-1 Kowakae,
Higashi-osaka, Japan Summary Various methods for postcolumn derivatization of carbohydrates for photometric (P), fluorimetric (F) and electrochemical (E) detection are summarized. The major methods include conversion to furfurals (with strong mineral acids, reducing carbohydrates, for P and F), etc., followed by condensation with appropriate chromogenic or fluorogenic reagents; direct or indirect coloration of leuco compounds (for P) or chelating agents (for P and E), respectively, by utilizing the reducibility of reducing carbohydrates; reactions with fluorogenic reagents such as aliphatic amines (for F), 2-cyanoacetamide (for P, F, and E), arginine (for F), benzamidines (for F), etc., in neutral or weakly alkaline media; and coloration of the condensates with hydrazino compounds in alkali (for P). The characteristic features of individual methods and their optimized conditions are reviewed.
Anal. Chem. 1985, 57, 224-229 COMPARATIVE STUDY OF POSTCOLUMN REACTIONS FOR THE DETECTION OF SACCHARIDES IN LIQUID CHROMATOGRAPHY
Petr Vratny, U.A. Th. Brinkman, and R. W. Frei*
Department of Analytical Chemistry, Free University, De Boelelaan 1083, 1081 HV Amsterdam, The Netherlands Summary The application of a new postcolumn derivatization reagent, p-aminobenzoic acid hydrazide (ABH), in the HPLC of saccharides is described. Comparative studies with other available reagents (disodium bicinchoninate, 2-cyanoacetamide, tetrazolium blue, and potassium hexacyanoferrate) indicate that for given instrumental conditions and sparation techniques the ABH reagent offers the best sensitivity. By use of a Ca2+ -loaded cation exchanger column and water as an eluent, detection limits in the range of 10-8 g have been reached. The inclusion of a solid phase catalytic reactor in the detection system permits detection of nonreducing oligo-saccharides (e.g., sucrose) as well as reducing oligo- and monosaccharides. Contributions of this catalytic reactor and of other system parts to the total band broadening for optimum eperimental conditions are given. Applications to real samples illustrate the increased specificity and sensitivity of this new postcolumn reaction in comparison with other detection methods.
Analytical Biochemistry 131, 492-498 (1983) MONITORING OF CARBOHYDRATES WITH PERIODATE IN EFFLUENTS FROM HIGH-PRESSURE LIQUID CHROMATOGRAPHY COLUMNS
Philip Nordin
Department of Biochemistry, Kansas Agricultural Experiment Station, Kansas State University, Manhattan, Kansas 66506
Summary Application of periodate to monitoring of carbohydrates in effluents from borate anion-exchange columns is described. The effect of temperature to speed the reaction in a postcolumn reactor was investigated at pH 5.0 and 8.6. The alkaline conditions increase sensitivity for some carbohydrates due to overoxidation. Temperatures up to 100°C may be employed to detect less reactive sugars such as cyclitols. Peaks are detected by an absorbance decrease at 260 nm with a high-pressure liquid chromatography detector. The reagent permits detection of a wide variety of carbohydrates, aldoses, cyclitols, and oligosaccharides with sensitivities of less than 1 nmol. Keywords: Carbohydrates;HPLC: periodate; analysis; monosaccharides
Analytical Biochemistry 198, 334-341 (1991) HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY OF MONOSACCHARIDES AND OLIGOSACCHARIDES IN A COMPLEX BIOLOGICAL MATRIX
Gijsbert O.H. Peelen, Jan G.N. de Jong, and Ron A. Wevers
University Hospital Nijmegen, Laboratory of Neurology and Paediatrics, Institute of Neurolory, Reinier Postlaan 4, 6525 GC Nijmegen The Netherlands
Summary Analysis of oligosaccharides in complex biological matrices is hampered by the fact that oligosaccharides, closely related in structure, are difficult to separate from each other and that conventional detection procedures (refraction index and uv detection) are not specific enough for carbohydrates. Prepurification of samples by procedures like desalting or gel filtration is often used but can lead to the loss of specific oligosaccharides. We have used pellicular anion chromatography in combination with a postcolumn reaction for reducing carbohydrates based on 4-aminobenzoylhydrazide. This procedure not only detected normal mono- and oligosaccharides but N-acetylhexosamines and reducing N-acetylhexosamine containing oligosaccharides as well. A sensitivity of an\bout 20-25 pmol for non-GlcNAc containing mono- or oligosaccharides and between 30-50 pmol for GlcNAc or oligosaccharides with GlcNAc at the reducing side was reached. The postcolumn detection was compared with pulsed amperometric detection and appeared to be more specific for mono- and oligosaccharides. Except for deproteination to protect the column, no further sample preparation was needed with this systemfor our application (urines). In this way pellicular anion chromatography in combination with this postcolumn reaction appeared to be a sensitive and specific HPLC procedure for analysis of monosaccharides and oligosaccharides in complex biological matrices.
Journal of Chromatography, 625 (1992) 151-155
Elsevier Science Publishers B.V., Amsterdam CHROM. 24 532 DETERMINATION OF CARBOHYDRATES BY HYDROPHILIC INTERACTION CHROMATOGRAPHY WITH PULSED AMPEROMETRIC DETECTION USING POSTCOLUMN pH ADJUSTMENT
Tomoyoshi Soga, Yoshinori Inoue and Kenji Yamaguchi
Analytical Instruments Division. Yokogawa Analytical Systems, 2-11-19 Nakacho, Musashino-shi, Tokyo (Japan)
Summary
An HPLC method for the determination of carbohydrates using a postcolumn pH adjustment technique with lithium hydroxide solution followed by pulsed amperometric detection was developed. In cojunction with hydrophilic interaction chromatography, the technique was used to determine reducing sugars, non-reducing sugars, and sugar alcohols. Detection limits from 0.7-2.7 ng with a signal-to-noise ratio of 3 were achieved. The relative standard deviation for peak area was better than 2.7%. The postcolumn pH adjustment technique enabled gradient elution to be used.
LC- MS 10th California Pesticide Residue Workshop, March 16-19, 1998, Yosemite, California APPLICATION OF AUTOMATED HPLC-MSn ANALYSIS IN THE IDENTIFICATION OF PESTICIDES
Dieter M. Drexler* and Philip R. Tiller
Finnigan Corporation, 355 River Oaks Parway, San Jose, California 95134. Overview Purpose
A confirmatory screening method for carbamate and urea pesticides was developed using HPLC/MS. This method was used to detect and to identify five representative compounds of the pesticides listed in the EPA Method 632(1) in a pesticide standard mix. Method
An HPLC/ion-trap mass spectrometer equipped with a positive ion atmospheric pressure chemical ionization source (PI-APCI) utilizing MS Full Scan and Data-Dependent MS/MS Full Scan modes. Results
LC-MS Full Scan data provide the retention times together with the molecular weights of the analytes and also reveal possible adducts. Data-Dependent MS/MS Full Scan data confirm the presence of suspected analytes through the detection of structurally significant fragment ions. This automated MSn technique permitted the development of high sensitivity and confirmatory screening methods for pesticide analysis utilizing an ion-trap mass spectrometer.
10th California Pesticide Residue Workshop, March 16-19, 1998, Yosemite, California PESTICIDE ANALYSIS BY BENCHTOP LC/MS/MS
Linda L. Lopez and Adrian P. Land
TheroQuest Finnigan, San Jose, California Overview Purpose
Rapidly identify and quantify hydrophilic pesticides in environmental water samples. Method
Full Scan Positive Ion LC/ESI/MS/MS Utilizing an Ion Trap Mass Spectrometer. Results
Full Scan LC/MS/MS permits quantitative analysis of hydrophilic pesticides in a single HPLC run with a greater degree of specificity than a conventional UV detector, providing the added benefit of structural information and permitting significantly more rapid method development. ^ Back to top |
