Determination of total serum sulfite by HPLC with fluorescence detection

1995 ◽  
Vol 41 (6) ◽  
pp. 897-903 ◽  
Author(s):  
A J Ji ◽  
S R Savon ◽  
D W Jacobsen
Keyword(s):  
Fluorescence Detection ◽  
Standard Addition ◽  
Normal Subjects ◽  
Reversed Phase ◽  
Pharmaceutical Products ◽  
Total Serum ◽  
Steroid Dependent ◽  
The Us ◽  
Serum Folic Acid

Abstract An estimated 500,000 individuals in the US, mostly steroid-dependent asthmatics, suffer severe adverse reactions to sulfites in foods, beverages, and pharmaceutical products. In an attempt to understand the pathogenesis of sulfite hypersensitivity, we have developed an assay for the determination of total serum sulfite by utilizing: (a) reductive release of serum protein-bound sulfite; (b) derivatization of free sulfite with monobromobimane; (c) separation of sulfite-bimane from thiol-bimanes by reversed-phase HPLC; and (d) quantitation of sulfite-bimane by fluorescence detection. The detection limit of this assay was 0.44 mumol/L serum sulfite. The intra- and interassay CVs for total serum sulfite at 5.4 mumol/L were 8.1% and 22.0%, respectively. The standard addition method was used to determine total serum sulfite in normal subjects. More than 70 samples were prepared in 2-3 h, followed by automated overnight analysis. The mean concentrations (+/- SD) of total serum sulfite in female (n = 41) and male (n = 35) donors were 4.63 +/- 2.33 and 5.16 +/- 2.68 mumol/L, respectively (not statistically significant: P = 0.368). The combined mean concentration of total sulfite in both sexes was 4.87 +/- 2.49 mumol/L. There was no correlation between total serum sulfite and total serum cysteine, cysteinylglycine, homocysteine, subject age, serum cobalamin, or serum folic acid. The reference range (mean +/- 2 SD) for total serum sulfite in normal subjects is 0-9.85 mumol/L.

scholarly journals The Determination of Six Ionophore Coccidiostats in Feed by Liquid Chromatography with Postcolumn Derivatisation and Spectrofotometric/Fluorescence Detection

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Małgorzata Olejnik ◽  
Piotr Jedziniak ◽  
Teresa Szprengier-Juszkiewicz
Keyword(s):  
Drug Resistance ◽  
Liquid Chromatography ◽  
Fluorescence Detection ◽  
Internal Standard ◽  
Reversed Phase ◽  
Feed Additives ◽  
Core Shell ◽  
Proficiency Tests ◽  
Reversed Phase Hplc

The control of levels of anticoccidial feed additives in targeted feeds plays an important role in the assurance of efficiency of animal treatment, prevention of drug resistance, and food safety. The robust and labour-efficient method for the simultaneous determination of six ionophore coccidiostats (lasalocid, maduramicin, monensin, narasin, salinomycin, and semduramicin) in targeted feed has been developed. Properly grinded and homogenized feed sample was spiked with internal standard (monesin methyl ester) and extracted with methanol. The extract was analysed with reversed phase HPLC without any further purification. The separation of the analytes with conventional C18 and core-shell columns was compared. Lasalocid was analysed with fluorescence detection, whereas other ionophores were detected with UV-Vis detector after derivatisation with vanillin in the presence of sulfuric acid. Fortified samples and targeted feeds at authorized levels were used for method validation. Recovery was in the range of 85–110%, depending on the analyte. The within-laboratory reproducibility did not exceed the target value from Horwitz equation. The results of the proficiency tests (z-scores in the range of −1.0 to 1.9) confirmed the reliability of the developed protocol.

scholarly journals Rapid Determination of Ampicillin in Bovine Milk by Liquid Chromatography with Fluorescence Detection

1997 ◽  
Vol 80 (1) ◽  
pp. 25-30 ◽  
Author(s):  
Catharina Y W Ang ◽  
Luo Wenhong
Keyword(s):  
Fluorescence Detection ◽  
Rapid Determination ◽  
Bovine Milk ◽  
Skim Milk ◽  
Reversed Phase ◽  
Coefficients Of Variation ◽  
Whole Milk ◽  
Liquid Chromatographic ◽  
Clear Supernatant

Abstract A rapid and sensitive liquid chromatographic (LC) method was developed for the determination of am- picillin residues in raw bovine milk, processed skim milk, and pasteurized, homogenized whole milk with vitamin D. Milk samples were deprote- inized with trichloroacetic acid (TCA) and acetonitrile. After centrifugation, the clear supernatant was reacted with formaldehyde and TCA under heat. The major fluorescent derivative of ampicillin was then determined by reversed-phase LC with fluorescence detection. Average recoveries of ampicillin fortified at 5,10, and 20 ppb (ng/mL) were all >85% with coefficients of variation <10%. Limits of detection ranged from 0.31 to 0.51 ppb and limits of quantitation, from 0.66 to 1.2 ppb. After appropriate validation, this method should be suitable for rapid analysis of milk for ampicillin residues at the tolerance level of 10 ppb.

Determination of urinary normetanephrine and metanephrine by radial-compression liquid chromatography and electrochemical detection.

1983 ◽  
Vol 29 (2) ◽  
pp. 305-309 ◽  
Author(s):  
P J Orsulak ◽  
P Kizuka ◽  
E Grab ◽  
J J Schildkraut
Keyword(s):  
Liquid Chromatography ◽  
Electrochemical Detection ◽  
Depressive Disorders ◽  
Internal Standard ◽  
Normal Subjects ◽  
Reversed Phase ◽  
Radial Compression ◽  
Ion Pair Chromatography ◽  
Catecholamine Metabolites

Abstract A procedure has been developed for determining the O-methylated catecholamine metabolites, normetanephrine and metanephrine, in urine by use of radial-compression liquid chromatography followed by electrochemical detection. Normetanephrine and metanephrine are isolated from hydrolyzed urine by ion-exchange on small, commercially available, disposable columns and preconcentrated by solvent extraction. They are then separated by reversed-phase ion-pair chromatography, with use of a radial compression cartridge and radial compression module, and quantified with 3-methoxy-4-hydroxybenzylamine as internal standard. Normetanephrine, metanephrine, and the internal standard are separated from interfering peaks in about 15 min. The method is applicable to the relatively low amounts of normetanephrine (100-600 micrograms/24 h) and metanephrine (50-400 micrograms/24 h) found in normal subjects and patients with depressive disorders or hypertension. Within-day CVs ranged from 1.1 to 2.2% for normetanephrine and 1.2 to 6.9% for metanephrine; the corresponding between-day CVs were 4.9 and 5.7% over these ranges.

Determination of Polynuclear Aromatic Hydrocarbons in Seafood by Liquid Chromatography with Fluorescence Detection

1992 ◽  
Vol 75 (5) ◽  
pp. 872-877 ◽  
Author(s):  
Gracia A Perfetti ◽  
Patricia J Nyman ◽  
Sheryl Fisher ◽  
Frank L Joe ◽  
Gregory W Diachenko
Keyword(s):  
Liquid Chromatography ◽  
Fluorescence Detection ◽  
Aromatic Hydrocarbons ◽  
Solid Phase ◽  
Reversed Phase ◽  
Polynuclear Aromatic Hydrocarbons ◽  
Matrix Interferences ◽  
Phase Liquid ◽  
Certified Values

Abstract Modification of a previously published method for determination of polynuclear aromatic hydrocarbons (PAHs) produces very clean seafood extracts in less than half the time. After alkaline digestion of the seafood, PAHs were partitioned into 1,1,2- trichlorotrifluoroethane. The resulting extract was cleaned up by solid-phase extraction on alumina, silica, and C18 adsorbents and then analyzed by gradient reversed-phase liquid chromatography with programmable fluorescence detection. Average recoveries of 12 PAHs [acenaphthene, anthracene, fluoranthene, pyrene, benz(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)- fluoranthene, benzo(a)pyrene, dibenz(a,h)anthracene, benzo(ghi)perylene, and indeno(1,2,3-cd)pyrene] from 5 different matrixes (mussels, oysters, clams, crabmeat, and salmon) spiked at low partsper- billion levels ranged from 76 to 94%. Estimated limits of quantitation ranged from 0.01 to 0.6 ppb PAHs in extracts that were free of matrix interferences. Results of analyses of a mussels standard reference material obtained from the National Institute of Standards and Technology were in good agreement with the certified values.

scholarly journals Determination of Sulfonamides in Edible Salmon Tissue by Liquid Chromatography with Postcolumn Derivatization and Fluorescence Detection

1997 ◽  
Vol 80 (4) ◽  
pp. 751-755 ◽  
Author(s):  
Theresa A Gehring ◽  
Larry G Rushing ◽  
Harold C Thompson
Keyword(s):  
Acetic Acid ◽  
Liquid Chromatography ◽  
Fluorescence Detection ◽  
Coho Salmon ◽  
Gradient Elution ◽  
Reversed Phase ◽  
Aqueous Acetic Acid ◽  
Postcolumn Derivatization

Abstract Fourteen sulfonamides—sulfanilamide, sulfadiazine, sulfathiazole, sulfapyridine, sulfam- erazine, sulfamethazine, sulfamethizole, sulfamethoxypyridazine, sulfachloropyridazine, sulfamonomethoxine, suļfadoxine, sulfamethoxazole, sulfadimethoxine, and sulfaquinoxoline—residues of which could be found in aquacultured species, were separated in <25 min by reversed-phase (C18) liquid chromatography (LC) with gradient elution. Analytes were extracted from edible salmon tissue (muscle and adhering skin) with acetonitrile—2% aqueous acetic acid, isolated with 2 liquid-liquid partitionings, and derivatized with fluorescamine after eluting from the column. The derivatives were detected by fluorescence. Recoveries (n = 4) from coho salmon fortified with sulfonamides at 5,10, and 20 ng/g tissue averaged 79.7± 7.3, 84.6 ± 7.7, and 88.2 ± 7.1%, respectively. Limits of quantitation were 5 ng/g tissue, for sulfanilamide, sulfamethoxypyridazine, and sulfaquinoxoline and 1 ng/g tissue for the remaining sulfonamides.

scholarly journals Multiresidue Determination of Fluoroquinolones in Eggs

2000 ◽  
Vol 83 (6) ◽  
pp. 1306-1312 ◽  
Author(s):  
Marilyn J Schneider ◽  
Dan J Donoghue
Keyword(s):  
Liquid Chromatography ◽  
Fluorescence Detection ◽  
Small Volume ◽  
Reversed Phase ◽  
Reversed Phase Liquid Chromatography ◽  
Trace Enrichment ◽  
On Line ◽  
Phase Liquid ◽  
Multiresidue Determination

Abstract A multiresidue method was developed for the determination of fluoroquinolones in eggs. Extraction of eggs with ammoniacal acetonitrile was followed by liquid–liquid defatting, solvent evaporation, and redissolution in a small volume of buffer. The fluoroquinolones were further purified by on-line microdialysis, concentrated on a trace enrichment column, and separated by reversed-phase liquid chromatography with fluorescence detection. Norfloxacin (NOR), ciprofloxacin (CIP), and sarafloxacin (SAR) were extracted from fortified eggs over a range of 2–200 μg/kg, with recoveries of 65.7–78.9%, 65.6–77.1%, and 67.6–110%, respectively. Enrofloxacin (ENRO) was extracted over a range of 1–100 μg/kg, with recoveries of 71.5–86.7%, whereas desethylene ciprofloxacin (DCIP) and danofloxacin (DANO) were extracted over a range of 0.2–20 μg/kg, with recoveries of 68.7–90.7% and 76.0–93.8%, respectively. The limits of quantitation for the 6 fluoroquinolones were as follows: DCIP and DANO, 0.3 μg/kg; ENRO, 1 μg/kg; NOR and CIP, 2 μg/kg; and SAR, 3 μg/kg. Both SAR and ENRO incurred eggs were also successfully analyzed using this method.

scholarly journals Simultaneous Determination of Hyoscine Butylbromide and Ketoprofen in Pharmaceutical Preparations by Spectrophotometric and Liquid Chromatographic Methods

2007 ◽  
Vol 90 (1) ◽  
pp. 102-112 ◽  
Author(s):  
Yasser Shaker El-Saharty ◽  
Fadia H Metwally ◽  
Mohamed Refaat ◽  
Sonia Zaki El-Khateeb
Keyword(s):  
Pharmaceutical Preparations ◽  
Standard Addition ◽  
Reversed Phase ◽  
Reversed Phase Liquid Chromatography ◽  
Hyoscine Butylbromide ◽  
Mathematical Algorithm ◽  
Accuracy And Precision ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract A binary mixture of hyoscine butylbromide and ketoprofen was determined by 4 different methods. The first involved determination of hyoscine butylbromide and ketoprofen using the ratio-spectra first-derivative spectrophotometric technique at 211 and 234 nm over the concentration ranges of 2-14 and 5-45 μg/mL with mean accuracies 99.84 ± 0.92 and 99.98 ± 0.64%, respectively. The second method utilized second-derivative spectrophotometry over the concentration ranges of 2-14 and 5-35 μg/mL with mean accuracies 99.32 ± 1.06 and 99.55 ± 1.15%, respectively. The third method was based on the resolution of the 2 components by bivariate calibration depending on a simple and rapid mathematical algorithm and quantitative evaluation of the absorbances at 206 and 254 nm over concentration ranges of 2-16 and 5-35 μg/mL; mean accuracies of 100.21 ± 1.30 and 100.19 ± 1.07% were obtained for hyoscine butylbromide and ketoprofen, respectively. The fourth method was reversed-phase liquid chromatography using 0.05 M ammonium dihydrogen phosphateacetonitrilemethanol (20 + 30 + 6, v/v) as the mobile phase with ultraviolet detection at 220 nm over concentration ranges of 1-90 and 5-70 μg/mL; mean accuracies were 99.92 ± 1.02 and 99.61 ± 0.98%, respectively. The suggested procedures were checked using laboratory-prepared mixtures and were successfully applied for the analysis of pharmaceutical preparations. The methods retained their accuracy and precision when the standard addition technique was applied. The results obtained by applying the proposed methods were statistically analyzed and compared with those obtained by the manufacturer's method.

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