Monolithic stationary phase coupled with coulometric detection: Development of an ion-pair HPLC method for the analysis of quinone-bearing compounds

2007 ◽  
Vol 30 (17) ◽  
pp. 2935-2942 ◽  
Author(s):  
Francesca Mancini ◽  
Maria L. Bolognesi ◽  
Carlo Melchiorre ◽  
Andrea Cavalli ◽  
Vincenza Andrisano
Keyword(s):  
Stationary Phase ◽  
Hplc Method ◽  
Ion Pair ◽  
Coulometric Detection ◽  
Monolithic Stationary Phase

scholarly journals Simultaneous determination of clobutinol hydrochloride and doxylamine succinate from syrups by RP HPLC using a new stationary phase containing embedded urea polar groups

2012 ◽  
Vol 48 (2) ◽  
pp. 315-323 ◽  
Author(s):  
Paulo Cesar Pires Rosa ◽  
Isabel Cristina Sales Fontes Jardim
Keyword(s):  
Stationary Phase ◽  
Simultaneous Determination ◽  
Reversed Phase ◽  
Hplc Method ◽  
Array Detector ◽  
Polar Groups ◽  
Ich Guidelines ◽  
Relative Standard ◽  
New Stationary Phase

A new, simple, fast, reproducible and sensitive reversed phase HPLC method, using a new stationary phase containing embedded urea polar groups, has been developed and validated for the simultaneous determination of clobutinol hydrochloride (CLO) and doxylamine succinate (DOX) in syrups. The determination was carried out on a C8 urea column (125 mm x 3.9 mm i.d., 5 µm particle size) synthetized at the Liquid Chomatography Laboratory (LabCrom) of the Chemistry Institute of Unicamp. The mobile phase consisted of a mixture of acetonitrile:methanol:phosphate buffer (pH 2.5) in the gradient mode. The diode array detector (DAD) was operated at 230 nm for CLO and 262 nm for DOX. The method showed adequate precision, with relative standard deviations (RSD) less than 1%. The presence of the excipients did not interfere in the results of the analysis. Accuracy was determined by adding standards of the drugs to a placebo and good recovery values were obtained. The analytical curves were linear (r² 0.9999 for CLO and 0.9998 for DOX) over a wide concentration range (2.4-336 µg mL-1 for CLO and 2.3-63 µg mL-1 for DOX). The solutions were stable for at least 72 hours at room temperature. The criteria for validation using the ICH guidelines were fulfilled.

Glutamate levels in cerebrospinal fluid in amyotrophic lateral sclerosis: a reappraisal using a new HPLC method with coulometric detection in a large cohort of patients

2002 ◽  
Vol 193 (2) ◽  
pp. 73-78 ◽  
Author(s):  
Odile Spreux-Varoquaux ◽  
Gilbert Bensimon ◽  
Lucette Lacomblez ◽  
François Salachas ◽  
Pierre François Pradat ◽  
...  
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Cerebrospinal Fluid ◽  
Hplc Method ◽  
Large Cohort ◽  
Coulometric Detection ◽  
Lateral Sclerosis

scholarly journals Monitoring the Levels of Biogenic Amines in Canned Fish Products Marketed in Ghana

2020 ◽  
Vol 2020 ◽  
pp. 1-6 ◽  
Author(s):  
Alexander Weremfo ◽  
Meinster Kodjo Eduafo ◽  
Hakim Agyei Gyimah ◽  
Samuel Abassah-Oppong
Keyword(s):  
Biogenic Amines ◽  
Hplc Method ◽  
Ion Pair ◽  
Human Consumption ◽  
Fish Products ◽  
Canned Fish ◽  
Relative Standard ◽  
Excellent Selectivity ◽  
Detection And Quantification

An ion-pair HPLC method with postcolumn o-phthalaldehyde (OPA) derivatization and fluorescence detection was validated for quantitative determination of five biogenic amines (histamine, tyramine, cadaverine, putrescine, and agmatine) in canned fish products (mackerel, sardine, and tuna) marketed in Ghana. The validated method exhibited excellent selectivity and good linearity (R2 > 0.9990) for all the amines. The limits of detection and quantification for studied biogenic amines were in the range of 0.32–0.78 mg·kg−1 and 1.10–2.57 mg·kg−1, respectively. Also, a satisfactory recovery was obtained for all the amines (82.1–101.4%), and the relative standard deviations were lower than 9.3% under repeatability conditions for the studied amines. Subsequently, the method was applied to the analysis of biogenic amines in canned fish products to estimate the safety of Ghanaian consumers. The maximum levels of histamine, tyramine, cadaverine, putrescine, and agmatine detected in the analysed canned fish products were 64.05 mg·kg−1, 27.44 mg·kg−1, 27.23 mg·kg−1, 18.74 mg·kg−1, and 52.72 mg·kg−1, respectively. Thus, the levels of biogenic amines detected in the canned fish products were lower than the acceptable levels and, therefore, can be considered relatively safe for human consumption.

scholarly journals Improved HPLC Conditions to Determine Eumelanin and Pheomelanin Contents in Biological Samples Using an Ion Pair Reagent

2020 ◽  
Vol 21 (14) ◽  
pp. 5134 ◽  
Author(s):  
Shosuke Ito ◽  
Sandra Del Bino ◽  
Tomohisa Hirobe ◽  
Kazumasa Wakamatsu
Keyword(s):  
Dicarboxylic Acid ◽  
Biological Samples ◽  
Potassium Phosphate ◽  
Structural Diversity ◽  
Tricarboxylic Acid ◽  
Reversed Phase ◽  
Hplc Method ◽  
Original Method ◽  
Ion Pair ◽  
Improved Method

Alkaline hydrogen peroxide oxidation (AHPO) of eumelanin and pheomelanin, two major classes of melanin pigments, affords pyrrole-2,3,5-tricarboxylic acid (PTCA), pyrrole-2,3-dicarboxylic acid (PDCA) and pyrrole-2,3,4,5-tetracarboxylic acid (PTeCA) from eumelanin and thiazole-2,4,5-tricarboxylic acid (TTCA) and thiazole-4,5-dicarboxylic acid (TDCA) from pheomelanin. Quantification of these five markers by HPLC provides useful information on the quantity and structural diversity of melanins in various biological samples. HPLC analysis of these markers using the original method of 0.1 M potassium phosphate buffer (pH 2.1):methanol = 99:1 (85:15 for PTeCA) on a reversed-phase column had some problems, including the short lifetime of the column and, except for the major eumelanin marker PTCA, other markers were occasionally overlapped by interfering peaks in samples containing only trace levels of these markers. These problems can be overcome by the addition of an ion pair reagent for anions, such as tetra-n-butylammonium bromide (1 mM), to retard the elution of di-, tri- and tetra-carboxylic acids. The methanol concentration was increased to 17% (30% for PTeCA) and the linearity, reproducibility, and recovery of the markers with this improved method is good to excellent. This improved HPLC method was compared to the original method using synthetic melanins, mouse hair, human hair, and human epidermal samples. In addition to PTCA, TTCA, a major marker for pheomelanin, showed excellent correlations between both HPLC methods. The other markers showed an attenuation of the interfering peaks with the improved method. We recommend this improved HPLC method for the quantitative analysis of melanin markers following AHPO because of its simplicity, accuracy, and reproducibility.

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