scholarly journals A simple method for the analysis of urinary sucralose for use in tests of intestinal permeability

2005 ◽  
Vol 42 (3) ◽  
pp. 224-226 ◽  
Author(s):  
A D G Anderson ◽  
P Poon ◽  
G M Greenway ◽  
J MacFie
Keyword(s):  
Refractive Index ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Simple Method ◽  
Standard Curve ◽  
Additional Information ◽  
Accuracy And Precision ◽  
Analytical Recovery ◽  
Peak Areas ◽  
Syringe Filter

Background: Sucralose is a unique disaccharide probe which is stable in the colon and can be used to assess permeability over the whole gut. Additional information can be gained when sucralose is administered in combination with lactulose and a monosaccharide such as L-rhamnose in the form of a 'triple sugar test.' We describe a simple assay for urinary sucralose by HPLC with refractive index detection (HPLC-RI). Methods: Phenyl-β-D-glucopyranoside (internal standard) was added to 10 mL of urine, which was then passed through a 0.45 μm syringe filter. Elution was with 30% methanol (1 mL/min) on a reverse-phase C18 column. Detection was by refractive index, and integration based upon peak areas. Sixty standards of sucralose in human urine were analysed in order to quantify analytical variation. Results: The standard curve for urinary sucralose was linear from 25 to 500 mg/L ( r>0.99). The limit of detection was 11 mg/L. Analytical recovery of sucralose at concentrations of 25, 50 and 100 mg/L was 101.5% (CV 7.59%), 102.9% (CV 5.82%) and 105.0% (CV 4.26%), respectively Conclusions: The technique described represents a simple assay for urinary sucralose which performed with acceptable accuracy and precision and should facilitate the use of the triple sugar test in clinical research.

Gas Chromatographic Profile Analysis of Basic Nitrogen-Containing Aromatic Compounds (Azaarenes) in High Protein Foods

1986 ◽  
Vol 69 (3) ◽  
pp. 537-541
Author(s):  
Gernot Grimmer ◽  
Klaus-Werner Naujack
Keyword(s):  
Aromatic Compounds ◽  
Limit Of Detection ◽  
Profile Analysis ◽  
Collaborative Study ◽  
Internal Standard ◽  
Exchange Chromatography ◽  
Basic Nitrogen ◽  
Chromatographic Profile ◽  
Polycyclic Aromatic ◽  
Peak Areas

Abstract A method is described for the determination of basic nitrogen-containing polycyclic aromatic compounds (N-PACs, azaarenes) in meat. The enrichment procedure includes liquid-liquid partition (dimethylformamide-water-cyclohexane), extraction of N-PACs by sulfuric acid, reextraction after neutralization by cyclohexane or, alternatively, by nonadsorbing ion exchange chromatography. Further purification is performed by column chromatography on Sephadex LH20 using a dosed system to avoid sample contamination by laboratory pollutants. N-PACs are analyzed by capillary gas chromatography and measured by comparing to the corresponding peak areas of an internal standard (e.g., lO-azabenzo(a)pyrene). The limit of detection of this method ranges from 0.1 to 0.4 ng for benzacridines, dibenzacridines, and their methyl derivatives. The results of a collaborative study, stimulated by IUPAC, are reported: Coefficients of variation for the various azaarenes were 4.0-13.6% for the check analysis and 10.4-25.4% for a spiked ham sample. Consequently, IUPAC suggests this procedure as a recommended method.

High-Performance Liquid-Chromatographic Measurement of Plasma Creatinine in Newborns

1992 ◽  
Vol 38 (1) ◽  
pp. 101-103 ◽  
Author(s):  
Paul H Scott
Keyword(s):  
High Performance ◽  
Linear Regression Analysis ◽  
Internal Standard ◽  
High Performance Liquid Chromatographic ◽  
Hplc Method ◽  
Exchange Chromatography ◽  
Plasma Creatinine ◽  
Standard Curve ◽  
Analytical Recovery ◽  
Liquid Chromatographic

Abstract This HPLC method for measuring plasma creatinine is based on cation-exchange chromatography and is particularly suitable for use with specimens from babies. A short chromatographic run is performed after simple protein precipitation with zinc sulfate and addition of an internal standard, N-methylnicotinamide. The standard curve for the method is linear up to 200 mumol/L, and analytical recovery of added creatinine is between 101% and 103%. Between-batch precision (CV) is less than 3% for mean creatinine values of 103 and 164 mumol/L. The method is free of interference from other metabolic components and drugs commonly used in neonates in routine clinical practice. Using specimens from neonates, I compared this method with a routinely used automated alkaline picrate method (from Randox Labs., performed on a Cobas MIRA analyzer). Linear-regression analysis yielded a correlation coefficient of 0.90, a slope of 1.00, and an intercept of +0.8 mumol/L. This HPLC method for creatinine should be of use in those circumstances where the alkaline picrate method is known to produce dubious results; however, the latter method is probably more suitable for routine use.

Gas-chromatographic determination of amantadine in human urine.

1980 ◽  
Vol 26 (2) ◽  
pp. 295-296 ◽  
Author(s):  
M J Stumph ◽  
M W Noall ◽  
V Knight
Keyword(s):  
Limit Of Detection ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Organic Layer ◽  
Liquid Chromatographic Method ◽  
Analytical Recovery ◽  
Instrument Response ◽  
Aqueous Layer ◽  
Liquid Chromatographic

Abstract We describe a gas--liquid-chromatographic method for determining the concentration of amantadine hydrochloride in urine with beta-phenylethylamine as internal standard. The urine sample is made alkaline and extracted with 0.5 mL of chloroform. After centrifugation the aqueous layer is aspirated, and an aliquot of the organic layer is injected directly into the gas chromatograph. Concentration and instrument response are linearly related between 2 and 125 mg/L. The limit of detection was 0.5 mg/L. Mean analytical recovery was calculated to be 97%.

Avidin-Biotin Enzyme Immunoassay of Osteocalcin in Serum or Plasma

1992 ◽  
Vol 38 (10) ◽  
pp. 1968-1974 ◽  
Author(s):  
J Jaouhari ◽  
F Schiele ◽  
S Dragacci ◽  
P Tarallo ◽  
J P Siest ◽  
...  
Keyword(s):  
Human Serum ◽  
Enzyme Immunoassay ◽  
Healthy Subjects ◽  
Limit Of Detection ◽  
Serum Concentrations ◽  
Calcium Dependent ◽  
Standard Curve ◽  
Microtiter Plates ◽  
Analytical Recovery ◽  
High Concentrations

Abstract We describe a competitive enzyme immunoassay, the ExtrAvidin-biotin system, for determining osteocalcin in human serum or plasma. Antibodies were raised against bovine osteocalcin. Binding of the antibodies to osteocalcin was calcium-dependent. Limit of detection is 0.07 nmol/L (0.4 microgram/L). The standard curve for method is linear between 0.3 and 17.6 nmol/L (1.9 and 100 micrograms/L). Interassay CV over the range 0.9 to 14.8 nmol/L (5.3 to 84 micrograms/L) is 7.5% to 11.7%. Analytical recovery is 105% +/- 5% (mean +/- SD). The measurement, which is adapted to microtiter plates, requires only 20 microL of serum and 5 h. The coefficient of correlation between the concentrations measured by this method and by a commercially available radioimmunoassay kit (CIS Biointernational) is 0.91. Osteocalcin can be measured in serum or heparinized plasma. Hemolysis (174 mumol/L hemoglobin) reduces osteocalcin concentration by 54%. High concentrations of triglycerides (7 mmol/L) give an overestimation of 63%. Serum concentrations of osteocalcin measured in 130 healthy subjects (ages 15-64 years) and 86 children (ages 4-14 years) were 1.4 +/- 0.8 and 4.0 +/- 1.5 nmol/L (8.1 +/- 4.6 and 22.5 +/- 8.6 micrograms/L), respectively (mean +/- SD).

scholarly journals Intact Parathyroid Hormone: Performance and Clinical Utility of an Automated Assay Based on High-Performance Immunoaffinity Chromatography and Chemiluminescence Detection

1992 ◽  
Vol 38 (8) ◽  
pp. 1494-1500 ◽  
Author(s):  
D S Hage ◽  
B Taylor ◽  
P C Kao
Keyword(s):  
Parathyroid Hormone ◽  
High Performance ◽  
Clinical Utility ◽  
Limit Of Detection ◽  
Intact Parathyroid Hormone ◽  
Automated Assay ◽  
Analytical Recovery ◽  
Peak Areas ◽  
Potential Use ◽  
Good Agreement

Abstract The performance and clinical utility of an automated assay of intact parathyroid hormone (parathyrin, PTH) are evaluated. The method is based on the extraction of PTH from plasma by an HPLC column containing immobilized anti-(44-68 PTH) antibodies. The PTH retained is detected with a postcolumn reactor and use of anti-(1-34 PTH) chemiluminescent-labeled antibodies. The total cycle time of the assay is 6.5 min per injection after a 1-h incubation. The lower limit of detection for PTH in a 66-microL plasma sample was 0.5 pmol/L based on peak heights and 0.2 pmol/L based on peak areas. Mean analytical recovery for PTH added to plasma was 97%. The within-day precisions (CVs) for 4.2 and 30 pmol/L PTH plasma samples were 9.2% and 5.6% and the day-to-day precisions were 10.3% and 5.7%, respectively. No significant interferences from 1-34, 44-68, or 53-84 PTH fragments were noted, even at highly increased concentrations of fragments. The correlation of results with those of a manual assay of intact PTH was 0.97, and the results showed good agreement with disease state for patients with hypo- or hyperparathyroidism. The specificity of the assay for primary hyperparathyroidism was greater than 95%. We discuss the advantages (speed and quality control) of this approach over current immunoassays and the potential use of this method for detecting other analytes.

Gas-chromatographic determination of amantadine in human urine.

1980 ◽  
Vol 26 (2) ◽  
pp. 295-296 ◽  
Author(s):  
M J Stumph ◽  
M W Noall ◽  
V Knight
Keyword(s):  
Limit Of Detection ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Organic Layer ◽  
Liquid Chromatographic Method ◽  
Analytical Recovery ◽  
Instrument Response ◽  
Aqueous Layer ◽  
Liquid Chromatographic

Abstract We describe a gas--liquid-chromatographic method for determining the concentration of amantadine hydrochloride in urine with beta-phenylethylamine as internal standard. The urine sample is made alkaline and extracted with 0.5 mL of chloroform. After centrifugation the aqueous layer is aspirated, and an aliquot of the organic layer is injected directly into the gas chromatograph. Concentration and instrument response are linearly related between 2 and 125 mg/L. The limit of detection was 0.5 mg/L. Mean analytical recovery was calculated to be 97%.

scholarly journals Development and Validation of an HPLC-UV Detection Assay for the Determination of Clonidine in Mouse Plasma and Its Application to a Pharmacokinetic Study

Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4109
Author(s):  
Haitham AlRabiah ◽  
Sabry M. Attia ◽  
Nasser S. Al-Shakliah ◽  
Gamal A. E. Mostafa
Keyword(s):  
Pharmacokinetic Study ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Reversed Phase ◽  
Linear Calibration ◽  
Mouse Plasma ◽  
Accuracy And Precision ◽  
Detection Assay ◽  
Development And Validation

An accurate and simple HPLC-UV method has been developed for the determination of clonidine in mouse plasma. A reversed phase C18 Nova Pack® column (125 mm × 4.6 mm i.d., × 3 μm particle size) was used as stationary phase. The mobile phase composition was a mixture of 0.1% diethylamine/acetonitrile (70:30, v/v) at pH 8 in an isocratic mode at flow rate was 1.0 mL/min. Detection was set at 210 nm. Tizanidine was used as an internal standard. The clonidine and tizanidine were extracted from plasma matrix using the deproteinization technique. The developed method exhibited a linear calibration range 100.0–2000 ng/mL and the lower limit of detection (LOD) and quantification (LOQ) were 31.0 and 91.9 ng/mL, respectively. The intra-day and inter-day accuracy and precision of the method were within 8.0% and 3.0%, respectively, relative to the nominal concentration. The developed method was validated with respect to linearity, accuracy, precision, and selectivity according to the US Food and drug guideline. Minimal degradation was demonstrated during the determination of clonidine under different stability conditions. The suggested method has been successfully applied during a pharmacokinetic study of clonidine in mouse plasma.

Rapid assay for amino acids in serum or urine by pre-column derivatization and reversed-phase liquid chromatography.

1982 ◽  
Vol 28 (3) ◽  
pp. 527-531 ◽  
Author(s):  
D C Turnell ◽  
J D Cooper
Keyword(s):  
Amino Acids ◽  
Liquid Chromatography ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Reversed Phase ◽  
Homocysteic Acid ◽  
Coefficients Of Variation ◽  
Peak Areas ◽  
Phase Liquid ◽  
The Mean

Abstract This method for estimating clinically important amino acids in serum or urine within 40 min involves o-phthalaldehyde/2-mercaptoethanol derivatization and reversed-phase "high-pressure" liquid chromatography. Homocysteic acid is an internal standard, and homoserine and norvaline are reference peaks. For all the amino acids estimated, the between-run coefficients of variation ranged from 2.0 to 13.5%, and the mean analytical recoveries from both serum and urine samples was 101%. Peak areas vary linearly with concentration up to 1500 mumol/L for all the amino acids assayed. The limit of detection for each amino acid was estimated to be 38 fmol.

Determination of promethazine in serum by liquid chromatography.

1981 ◽  
Vol 27 (2) ◽  
pp. 253-255 ◽  
Author(s):  
J E Wallace ◽  
E L Shimek ◽  
S C Harris ◽  
S Stavchansky
Keyword(s):  
Limit Of Detection ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Rectal Administration ◽  
Single Extraction ◽  
Analytical Recovery ◽  
Promethazine Hydrochloride ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract We describe a procedure for the liquid-chromatographic determination of promethazine in low-nanogram concentrations in serum. Triflupromazine is used as the internal standard. The method is based on a single extraction of promethazine from serum with hexane and subsequent derivatization with trichloroethyl chloroformate. Analytical recovery of promethazine is about 90%. The lower limit of detection is 1 microgram/L when a 2.0-mL aliquot of serum is assayed. Our data illustrate the practicability of the method for bioavailability studies after oral or rectal administration of promethazine hydrochloride.

Gas Chromatographic Detection of the Mycotoxin Zearalenone in Blood Serum

1980 ◽  
Vol 63 (3) ◽  
pp. 604-611
Author(s):  
H Locksley Trenholm ◽  
Robert Warner ◽  
Edward R Farnworth
Keyword(s):  
Blood Serum ◽  
Standard Procedure ◽  
Internal Standard ◽  
Detector Response ◽  
Acid Extraction ◽  
Standard Curve ◽  
Percent Recovery ◽  
Peak Areas ◽  
Chromatographic Detection ◽  
Gas Chromatographic Method

Abstract A sensitive gas chromatographic method for the quantitative analysis of zearalenone in blood serum is described. Zearalenone is eluted from blood serum by column chromatography followed by base-acid extraction with dichloromethane as the organic phase. After epicoprostanol (internal standard) is added, the sample is evaporated to dryness, derivatized, and injected onto the gas chromatographic column. A number of silylating agents and reaction conditions were investigated. Derivatizing zearalenone with N-methyl-N-trimethylsilyltrifluoroacetamide in the presence of acetone at room temperature for at least 2 hr gave best results. Sensitivity limit is <0.5 ng injected, equivalent to 100 ng zearalenone/mL blood serum. A linear standard curve is observed when 0.5–30 ng zearalenone derivative is injected onto the Perkin-Elmer gas chromatograph. For quantitation, a standard curve is prepared by plotting amounts of zearalenone (ng) injected vs. ratios for peak areas of zearalenone and epicoprostanol derivatives. The internal standard procedure improves the precision by minimizing variations in sample injections and detector response. Percent recovery from blood serum is 68–75 in the range of 1.6–8.0 Mg zearalenone/mL blood

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