Excretion of L-Dopa and Its Metabolites in Urine of Parkinson's Disease Patients Receiving L-Dopa Therapy

1971 ◽  
Vol 17 (9) ◽  
pp. 867-871 ◽  
Author(s):  
J I Routh ◽  
R E Bannow ◽  
R W Fincham ◽  
J L Stoll
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Cation Exchange ◽  
Anion Exchange ◽  
Paper Electrophoresis ◽  
Colorimetric Determination ◽  
Anion Exchange Column ◽  
Exchange Column ◽  
Cation Exchange Column

Abstract L-Dopa and its major metabolites were separated from daily 24-h urines from patients with Parkinson’s disease, who were being treated with increasing doses of the drug, up to 4 g per day. An aliquot of each sample was passed through three different ion-exchange columns. Catecholamines (dopamine, epinephrine, norepinephrine, metanephrine, and normetanephrine) were retained on a cation-exchange column, eluted with boric acid, and quantitated by fluorometric analysis. Catechol acids, present in the effluent of the cation-exchange column, were retained on an anion-exchange column. An aliquot of the eluate of the anion-exchange column was used for colorimetric determination of 3,4-dihydroxyphenylacetic acid, while the effluent from this column was used for colorimetric determination of dopa. A second aliquot of the eluate from this column was passed over a column of alumina, which retained all the acidic metabolites except homovanillic acid, which was measured fluorometrically in the effluent from the alumina column. Vanilmandelic acid was determined in another aliquot of each urine sample by use of paper electrophoresis. The excretion pattern elicited suggests a major metabolic pathway for the L-dopa administered to patients with Parkinson's disease.

scholarly journals Ion Chromatographic Method for the Simultaneous Determination of Anions and Cations in Firecrackers and Matches Samples as Known Potential Explosives

2019 ◽  
Vol 15 (1) ◽  
pp. 138
Author(s):  
Muhammad Amin ◽  
Lee Wah Lim
Keyword(s):  
Cation Exchange ◽  
Anion Exchange ◽  
Mobile Phase ◽  
Limit Of Detection ◽  
Reference Method ◽  
Anion Exchange Column ◽  
Exchange Column ◽  
Relative Standard ◽  
Cation Exchange Column

<p class="Abstract">A reference ion chromatography method based on column switching has been presented for the simultaneous determining anions (Cl<sup>−</sup>, ClO<sub>3</sub><sup>−</sup>, NO<sub>2</sub><sup>−</sup>, SO<sub>4</sub><sup>2</sup><sup>−</sup>, and NO<sub>3</sub><sup>−</sup>) and/or cations (NH<sub>4</sub><sup>+</sup>, Na<sup>+</sup>, K<sup>+</sup>, Ca<sup>2+</sup>, and Mg<sup>2+</sup>) using one pump, one type of mobile phase, and one detector. The reference method performed anion-exchange column and cation-exchange column and arranged serially via one 10-port valve. The determination of either anions or cations in one determination system could be made by switching the valve. When the use of 1.25 mM trimellitic acid as a mobile phase and the instrument was operated at a flow rate of 0.6 mL/min, five anions and five cations were determined on the anion-exchange column and the cation-exchange column, respectively. All anions target could be determined completely within 55 minutes, whereas the cations target could be determined within 35 minutes. The calculation of limit of detection using S/N=3 was 3.85 − 14.10 µM for anions and 2.95 − 10.58 µM for cations. The relative standard deviations of all ions were less than 3.82%, 3.29%, and 3.21% for retention time, peak area, and peak height, respectively. The reference method was then applied for the simultaneous determining anions and/or cations contained in firecrackers and matches samples as known potentially explosives.</p>

Determination of haemoglobin A1c by liquid chromatography using a new cation-exchange column

2003 ◽  
Vol 791 (1-2) ◽  
pp. 73-83 ◽  
Author(s):  
Maria Beatriz de la Calle Guntiñas ◽  
René Wissiack ◽  
Guy Bordin ◽  
Adela Rosa Rodrı́guez
Keyword(s):  
Liquid Chromatography ◽  
Cation Exchange ◽  
Haemoglobin A1c ◽  
Exchange Column ◽  
Cation Exchange Column

ANALYSIS FOR SMALL AMOUNTS OF CALCIUM, MAGNESIUM, BARIUM, AND SULPHATE USING PHTHALEIN PURPLE

1956 ◽  
Vol 34 (7) ◽  
pp. 921-925 ◽  
Author(s):  
J. R. McCallum
Keyword(s):  
Cation Exchange ◽  
Distilled Water ◽  
Complexometric Method ◽  
Exchange Column ◽  
Cation Exchange Column ◽  
Calcium Magnesium

For the determination of sulphate ion in samples containing 3 to 20 mgm., it was found that the standard precipitation techniques did not give sufficiently accurate results, and were time consuming. Reference to the literature showed that with certain modifications a complexometric method proposed by Schwarzenbach etal. for samples containing 20 to 50 mgm. of sulphate was most likely to give accurate results rapidly. In this method the sample is passed through a cation exchange column and washed with distilled water into a flask. This solution is boiled and precipitated with excess standard disodium ethylenediaminetetracetate in the presence of alcohol and ammonia using phthalein purple indicator. Provided that the details of procedure described in this paper are closely adhered to, accuracy is usually within two per cent. Calcium, magnesium, and barium may also be titrated directly using the phthalein purple indicator.

Gas Chromatographic Determination of N-Nitrosodialkanolamines in Herbicide Di- or Trialkanolamine Formulations

1988 ◽  
Vol 71 (2) ◽  
pp. 328-333
Author(s):  
Yuk Y Wigfield ◽  
Mario D Lacfloix ◽  
Monique Lanouette ◽  
Narine P Gurprasad
Keyword(s):  
Chromatographic Determination ◽  
Aqueous Sample ◽  
Anion Exchange Column ◽  
Exchange Column ◽  
Modified Method ◽  
Extraction Tube ◽  
Cation Exchange Column ◽  
Aqueous Layer ◽  
Tms Derivatives

Abstract A modified method is presented to determine trace quantities of N-nitrosodiethanolamine (NDE1A) and yV-nitrosodiisopropanolamine (NDiPlA) in the triisopropanolamine (TiPlA) formulation of a mixture of picloram and 2,4-D. Aqueous sample is extracted with dichloromethane to remove organic interferences, and then the aqueous layer is passed sequentially through chloride anion exchange column, hydrogen cation exchange column, and Clin-Elut extraction tube. The final eluate, 10% acetone in ethyl acetate, is concentrated. The isolated nitrosamines are converted to the corresponding trimethylsilyl (TMS) derivatives and determined by gas chromatography (GC) on a DB1 column coupled with a thermal energy analyzer (GC-TEA). Eight samples of commercial TiPlA formulations are analyzed. Maximum detected levels of NDE1A and NDiPlA were 0.6 and 0.9 ppm, respectively, expressed relative to total weight of active ingredients. Analysis of 13 samples of herbicide DEIA formulation using a previously established method and a DB225 column gave NDE1A results of 0.7-6.0 ppm. NDiPlA was not detected in those samples. Results are confirmed by GC-mass spectrometry (GC/MS) with oxygen negative chemical ionization (ONCI) detection. Dectection limits for both nitrosamines are 0.05 or 0.07 ng (0.1 or 0.17 ppm) for GC-TEA detection, depending on the analytical columns used, and 20 pg (0.04 ppm) for GC/MS detection. Recoveries of NDE1A are 87-109% for DEIA formulation spiked at 2.6 and 3.9 ppm and 90-115% for TiPlA formulation spiked at 0.2-0.3 ppm. Similarly, recoveries of NDiPlA are 95.7-100% for the DEIA formulation spiked at 0.24 and 0.48 ppm, and 82-118% for the TiPlA formulation spiked at 0.2-0.3 ppm.

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