scholarly journals Determination of 4-Hexylresorcinol in Shrimp by Liquid Chromatography with Fluorescence Detection

2000 ◽  
Vol 83 (1) ◽  
pp. 241-244 ◽  
Author(s):  
Klaas M Jonker ◽  
Colinda P Dekker
Keyword(s):  
Liquid Chromatography ◽  
Chromatographic Analysis ◽  
Reversed Phase ◽  
Fluorimetric Detection ◽  
Relative Standard ◽  
Liquid Chromatographic Analysis ◽  
Liquid Chromatographic ◽  
Phase Column ◽  
Reversed Phase Column

Abstract A method was developed to determine 4-hexylresorcinol in shrimp meat. The procedure is based on extraction of test portions with methanol followed by liquid chromatographic analysis of the extracts, using a reversed-phase column and fluorimetric detection (excitation: 280 nm, and emission: 310 nm). The confidence interval of the recovery in working range of 1.5–2.5 mg/kg was 81.6 ± 0.8%. The relative standard deviation in the working range was 2.1%. Limits of quantitation and detection were 6.59 and 1.98 ng/mL extract, respectively, corresponding to 0.26 and 0.08 mg/kg in shrimp.

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.

Determination of Cymiazole Residues in Honey by Liquid Chromatography

1993 ◽  
Vol 76 (1) ◽  
pp. 92-94 ◽  
Author(s):  
Paolo Cabras ◽  
Marinella Melis ◽  
Lorenzo Spanedda
Keyword(s):  
Liquid Chromatography ◽  
Chromatographic Analysis ◽  
Mobile Phase ◽  
Chromatographic Method ◽  
Reversed Phase ◽  
Limit Of Determination ◽  
Liquid Chromatographic Method ◽  
Liquid Chromatographic ◽  
Control Samples

Abstract A liquid chromatographic method is described for the determination of cymiazole residues in honey. This acaricide is determined on a reversed-phase (C18) column, with a CH3CN-O.OOIN HCI-NaCI mixture (950 mL + 50 mL + 0.3 g/L) as the mobile phase, and UV detection at 265 nm. Cymiazole is extracted with n-hexane from aqueous alkalinized (pH 9) honey solutions. No further cleanup of the honey extract was required before chromatographic analysis. Recoveries on control samples fortified with 0.01,0.10, and 1.00 ppm cymiazole ranged from 92 to 102%. The limit of determination was 0.01 ppm.

Improved liquid-chromatographic determination of caffeine in plasma.

1980 ◽  
Vol 26 (9) ◽  
pp. 1351-1354 ◽  
Author(s):  
J Blanchard ◽  
J D Mohammadi ◽  
K A Conrad
Keyword(s):  
Plasma Sample ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Small Sample ◽  
Small Animals ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Phase Column ◽  
Reversed Phase Column

Abstract We describe a rapid, specific, and sensitive liquid-chromatographic micro-method for caffeine in plasma. Each plasma sample can be assayed within about 15 min of its receipt. Samples are denatured with acetonitrile, centrifuged, and the supernate is chromatographed on a reversed-phase column. Only 100 microL of plasma is required, and concentrations as low as 0.3 mg/L can be measured accurately. Other xanthines and their metabolites do not interfere. The small sample required makes the procedure ideally suited for measuring caffeine in the plasma of infants and small animals as well as adults.

scholarly journals Rapid Postcolumn Methodology for Determination of Paralytic Shellfish Toxins in Shellfish Tissue

2008 ◽  
Vol 91 (3) ◽  
pp. 589-597 ◽  
Author(s):  
Wade A Rourke ◽  
Cory J Murphy ◽  
Ginette Pitcher ◽  
Jeffery M van de Riet ◽  
B Garth Burns ◽  
...  
Keyword(s):  
Reversed Phase ◽  
Mouse Bioassay ◽  
Working Standard ◽  
Shellfish Toxins ◽  
Paralytic Shellfish Toxins ◽  
Paralytic Shellfish ◽  
Relative Standard ◽  
Phase Column ◽  
Reversed Phase Column

Abstract A rapid liquid chromatographic (LC) method with postcolumn oxidation and fluorescence detection (excitation 330 nm, emission 390 nm) for the determination of paralytic shellfish toxins (PSTs) in shellfish tissue has been developed. Extracts prepared for mouse bioassay (MBA) were treated with trichloroacetic acid to precipitate protein, centrifuged, and pH-adjusted for LC analysis. Saxitoxin (STX), neoSTX (NEO), decarbamoylSTX (dcSTX), and the gonyautoxins, GTX1, GTX2, GTX3, GTX4, GTX5, dcGTX2, and dcGTX3, were separated on a polar-linked alkyl reversed-phase column using a step gradient elution; the N-sulfocarbamoyl GTXs, C1, C2, C3, and C4, were determined on a C-8 reversed-phase column in the isocratic mode. Relative toxicities were used to determine STX-dihydrochloride salt (diHCl) equivalents (STXeq). Calibration graphs were linear for all toxins studied with STX showing a correlation coefficient of 0.999 and linearity between 0.18 and 5.9 ng STX-diHCl injected (equivalent to 3.9128 g STXeq/100 g in tissue). Detection limits for individual toxins ranged from 0.07 g STXeq/100 g for C1 and C3 to 4.1 g STXeq/100 g for GTX1. Spike recoveries ranged from 76 to 112 in mussel tissue. The relative standard deviation (RSD) of repeated injections of GTX and STX working standard solutions was <4. Uncertainty of measurement at a level of 195 g STXeq/100 g was 9, and within-laboratory reproducibility expressed as RSD was 4.6 using the same material. Repeatability of a 65 g STXeq/100 g sample was 3.0 RSD. Seventy-three samples were analyzed by the new postcolumn method and both AOAC Official Methods for PST determination: the MBA (y = 1.22x + 13.99, r2 = 0.86) and the precolumn LC oxidation method of Lawrence (y = 2.06x + 12.21, r2 = 0.82).

scholarly journals Assay of Biogenic Amines Involved in Fish Decomposition

1996 ◽  
Vol 79 (1) ◽  
pp. 43-49 ◽  
Author(s):  
Pierre Malle ◽  
Michel Vallé ◽  
Stephane Bouquelet
Keyword(s):  
Quantitative Determination ◽  
Quality Index ◽  
Reversed Phase ◽  
Alkaline Ph ◽  
Specific Criterion ◽  
Species Specific ◽  
Liquid Chromatographic ◽  
Phase Column ◽  
Reversed Phase Column

Abstract A liquid chromatographic (LC) method is described for quantitative determination of putrefaction amines: putrescine, cadaverine, histamine, spermidine, and spermine. These amines are extracted from fish bygrinding with perchloric acid at -20°C. The amines are reacted with dansyl chloride at alkaline pH, dried under a stream of nitrogen, placed in an automatic injector at -20°C, and separated ina Kromasil C18 reversed-phase column at 25°C. A new gradient elutes the amines in 22 min and regenerates the column in 30 min. Regression lines are obtained with high coefficients of correlation. This method is faster and more reproducible than other methods and shows that the quality index is a reliable, albeit species-specific, criterion of fish decomposition.

Liquid-chromatographic assay of urinary 5-hydroxy-3-indoleacetic acid, with electrochemical detection.

1980 ◽  
Vol 26 (7) ◽  
pp. 907-909 ◽  
Author(s):  
Z K Shihabi ◽  
J Scaro
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Electrochemical Detection ◽  
High Performance ◽  
Indoleacetic Acid ◽  
Reversed Phase ◽  
Solvent Mixtures ◽  
Liquid Chromatographic ◽  
Phase Column ◽  
Reversed Phase Column

Abstract After extraction with two organic solvent mixtures, urinary 5-hydroxy-3-indoleacetic acid can be assayed by "high-performance" liquid chromatography on a reversed-phase column, with electrochemical detection. Compared to the nitrosonaphthol method (J. Biol. Chem. 216: 499, 1955), this method is more specific for detection of patients with carcinoid tumors.

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