Improved simultaneous gas-chromatographic analysis for homovanillic acid and vanillylmandelic acid in urine.

1981 ◽  
Vol 27 (12) ◽  
pp. 2029-2032 ◽  
Author(s):  
C Leiendecker-Foster ◽  
E F Freier
Keyword(s):  
Chromatographic Analysis ◽  
Homovanillic Acid ◽  
Chromatographic Method ◽  
Vanillylmandelic Acid ◽  
Precision Data ◽  
Hydroxyphenylacetic Acid ◽  
Catecholamine Metabolites ◽  
Gas Chromatographic Method ◽  
Improved Technique ◽  
Related Compounds

Abstract We describe an improved gas-chromatographic method for the simultaneous quantitation of the catecholamine metabolites, homovanillic acid (3-methoxy-4-hydroxyphenylacetic acid) and vanillylmandelic acid (3-methoxy-4-hydroxymandelic acid). Our improvements in the method of Muskiet et al. (Clin. Chem. 23: 863, 1977) include a shorter program time and a longer silylation interval. Recovery and precision data obtained by this improved technique are similar to those of Muskiet et al. Vanillylmandelic acid results (y) were compared with those by the method of Pisano et al. (Clin. Chim. Acta 7: 285, 1962). The relation is expressed by the equation y = 0.52 + 1.05x (Sy . x = 2.33 mg/24 h and r = 0.997). Results for homovanillic acid (y) were compared with those by the method of Knight and Haymond (Clin. Chem. 23: 2007, 1977); the equation was y = 0.84 + 0.90x (Sy . x = 2.04 and r = 0.97). Retention times are also reported for several phenolic acids and other related compounds found in urine.

Urinary 3-methoxy-4-hydroxyphenylacetic (homovanillic) and 3-methoxy-4-hydroxymandelic (vanillylmandelic) acids: gas-liquid chromatographic methods and experience with 13 cases of neuroblastoma.

1977 ◽  
Vol 23 (12) ◽  
pp. 2247-2249 ◽  
Author(s):  
M A Brewster ◽  
D H Berry ◽  
M Moriarty
Keyword(s):  
Homovanillic Acid ◽  
Chromatographic Method ◽  
Internal Standard ◽  
Silyl Ether ◽  
Vanillylmandelic Acid ◽  
Ether Extraction ◽  
Analytical Recovery ◽  
Hydroxyphenylacetic Acid ◽  
Gas Chromatographic Method ◽  
Liquid Chromatographic

Abstract We present a quantitative gas-chromatographic method for determining urinary 3-methoxy-4-hydroxymandelic acid (vanillylmandelic acid) and 3-methoxy-4-hydroxyphenylacetic acid (homovanillic acid). In this rapid technique an internal standard is used and the procedure involves ether extraction and silyl ether formation. Analytical recovery of vanillylmandelic acid averages 87.5% (CV, 0.95%), of homovanillic acid 102.3% (CV, 9.95%). Our data on 34 samples from 13 neuroblastoma patients show that homovanillic acid is more consistently elevated than is vanillylmandelic acid.

Evaluation of a Gas Chromatographic Method to Identify Irradiated Chicken, Pork, and Beef by Detection of Volatile Hydrocarbons

1994 ◽  
Vol 77 (5) ◽  
pp. 1202-1217 ◽  
Author(s):  
Georg A Schreiber ◽  
Grit Schulzki ◽  
Almuth Spiegelberg ◽  
Norbert Helle ◽  
Klaus W Bögl
Keyword(s):  
Chromatographic Analysis ◽  
Chromatographic Method ◽  
Dose Range ◽  
Correct Identification ◽  
Volatile Hydrocarbons ◽  
Chicken Carcass ◽  
Irradiation Treatment ◽  
Radiation Induced ◽  
Fat Fraction ◽  
Gas Chromatographic Method

Abstract A method suitable for routine application was used in an interlaboratory study to detect irradiation treatment of chicken carcass, pork, and beef. By using gas chromatographic analysis, 17 participating laboratories determined the quantity of 4 different radiation-induced volatile hydrocarbons (tetradecene, pentadecane, hexadecadiene, and neptadecene) in the fat fraction of coded specimens approximately 3 and 6 months after irradiation. The specimens of each type of meat were supplied by 2 different producers. The dose range tested (0.6-7.5 kGy) included levels commercially used to reduce the number of contaminating microorganisms (1-5 kGy). The method employed permitted a correct identification of irradiated or nonirradiated in 98.3% of the 864 specimens.

scholarly journals Rapid Gas Chromatographic Method for Simultaneous Determination of Cholesterol and α-Tocopherol in Eggs

1998 ◽  
Vol 81 (6) ◽  
pp. 1177-1184 ◽  
Author(s):  
Nickos Botsoglou ◽  
Dimitrios Fletouris ◽  
Ioannis Psomas ◽  
Antonios Mantis
Keyword(s):  
Simultaneous Determination ◽  
Chromatographic Method ◽  
Labor Cost ◽  
Precision Data ◽  
Total Analysis Time ◽  
Accuracy And Precision ◽  
Relative Standard ◽  
Total Analysis ◽  
Gas Chromatographic Method

Abstract A new method was developed for simultaneous determination of cholesterol and α-tocopherol in eggs. It involves rapid and simple sample preparation accomplished in one tube and chromatographic separation that does not require derivatization of analytes. Total analysis time per sample is 40 min. Labor, cost, and use of hazardous chemicals are minimized. To ensure selectivity, accuracy, and precision, critical analytical parameters were investigated. Overall recoveries were 98.8 and 99.2% for cholesterol and α-tocopherol, respectively. Linearity was acceptable for both analytes (r = 0.9964 for cholesterol and 0.9996 for α-tocopherol) in the fortification range examined. Precision data based on within-day and between-days variation gave overall relative standard deviations of 2.0% for cholesterol and 7.0% for α-tocopherol.The method was applied successfully for quantitation of cholesterol and α-tocopherol in eggs.

Gas Chromatographic Determination of Dioxathion and Chlorfenvinphos in Emulsifiable Formulations and Livestock Dips

1970 ◽  
Vol 53 (3) ◽  
pp. 566-568
Author(s):  
J E Paterson
Keyword(s):  
Quantitative Determination ◽  
Chromatographic Analysis ◽  
Chromatographic Method ◽  
Silicone Oil ◽  
Chromatographic Determination ◽  
Ionization Detector ◽  
Flame Ionization ◽  
Coefficients Of Variation ◽  
Gas Chromatographic Method

Abstract A gas chromatographic method is described for the quantitative determination of dioxathion and chlorfenvinphos in emulsifiable concentrates and livestock dips. A convenient quantity of the emulsifiable formulation is dissolved in xylene and the aqueous dip is extracted with xylene for gas chromatographic analysis, using a mixed silicone oil stationary phase and a flame ionization detector. The coefficients of variation for the dioxathion and chlorfenvinphos determinations in the emulsifiable concentrate are 2.4 and 1.0%, respectively. Recoveries of the former from a fouled dip ranged from 97 to 103% and recoveries of the latter ranged from 92 to 97%.

Gas chromatographic method for the determination of residues of chlordanes and related compounds in fish and shellfish

1980 ◽  
Vol 25 (1) ◽  
pp. 305-312 ◽  
Author(s):  
Tomoyuki Miyazaki ◽  
Kazuyuki Akiyama ◽  
Sciji Kaneko ◽  
Shozo Horii ◽  
Tatsunori Yamagishi ◽  
...  
Keyword(s):  
Chromatographic Method ◽  
Gas Chromatographic Method ◽  
Fish And Shellfish ◽  
Related Compounds

EXCRETION OF CATECHOLAMINE METABOLITES BY CHILDREN WITH FAMILIAL DYSAUTONOMIA

PEDIATRICS ◽  
1970 ◽  
Vol 46 (4) ◽  
pp. 513-522
Author(s):  
Stanley E. Gitlow ◽  
Laura M. Bertani ◽  
Elizabeth Wilk ◽  
Biao Lan Li ◽  
Stanley Dziedzic
Keyword(s):  
Homovanillic Acid ◽  
Matched Control ◽  
Normal Subjects ◽  
Biochemical Parameter ◽  
Familial Dysautonomia ◽  
Catecholamine Metabolism ◽  
Vanillylmandelic Acid ◽  
Sensitive Assay ◽  
Specific Nature ◽  
Catecholamine Metabolites

Although a defect in catecholamine metabolism has been suggested in familial dysautonomia, the specific nature and extent of this abnormality has not been defined. Highly specific and sensitive assay techniques were used to measure the excretion of vanillylmandelic acid (VMA), 3-methoxy-4-hydroxyphenylethyleneglycol (HMPG), total metanephrines (TM), normetanephrine (NM), and homovanillic acid (HVA) of 52 dysautonomic patients and 180 normal subjects. Twenty parents of dysautonomic patients and age-matched control subjects were studied similarly. Patients with familial dysautonomia were found to excrete elevated quantities of HVA, diminished quantities of VMA and HMPG, and normal amounts of TM and NM in comparison with normal subjects. The excretion of the sum of the deaminated catecholamine metabolites proved to be more aberrant in familial dysautonomia than any other biochemical parameter measured. The findings of this study are more compatible with an abnormality in catecholamine synthesis rather than in release. Parents of dysautonomic subjects excreted normal amounts of vanillylmandelic acid and homovanillic acid.

Improved determination of phenobarbital, primidone, and phenytoin by use of a preparative instrument for extraction, followed by gas chromatography.

1979 ◽  
Vol 25 (8) ◽  
pp. 1373-1376 ◽  
Author(s):  
L M St Onge ◽  
E Dolar ◽  
M A Anglim ◽  
C J Least
Keyword(s):  
Chromatographic Analysis ◽  
Chromatographic Method ◽  
Solid Phase ◽  
Correlation Coefficients ◽  
Specific Method ◽  
Sensitive Detector ◽  
Gas Chromatograph ◽  
Solid Phase Extraction Cartridge ◽  
Gas Chromatographic Method

Abstract A microprocessor-controlled automatic extractor, (PREMTM I) is described with which lipophilic components may be extracted from physiological fluids by means of a selective, solid-phase extraction cartridge, and the extracts presented in dry form for subsequent analysis. This instrument has been successfully evaluated for the extraction of phenobarbital, primidone, and phenytoin from human serum before chromatographic analysis. We describe a specific method for determination of these anticonvulsants, involving the PREP I and analysis, after flash-heater methylation, in a gas chromatograph equipped with a nitrogen-sensitive detector. Absolute recoveries ranged from 90 to 102%. Within-day and day-to-day precision (CV) ranged from 4 to 7% for all three drugs in therapeutic concentrations. Comparison of this method with results obtained with a liquid--liquid micro-scale extraction and a similar gas-chromatographic method resulted in correlation coefficients of 0.988 (phenobarbital), 0.978 (primidone), and 0.982 (phenytoin). These drugs in therapeutic concentrations can be simultaneously extracted and measured with confidence.

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