The "ultra-free" ultrafiltration technique compared with equilibrium dialysis for determination of unbound thiopental concentrations in serum.

1981 ◽  
Vol 27 (1) ◽  
pp. 166-168 ◽  
Author(s):  
D Jung ◽  
M Mayersohn ◽  
D Perrier
Keyword(s):  
Room Temperature ◽  
Serum Proteins ◽  
Classical Method ◽  
Equilibrium Dialysis ◽  
Clinical Measurement ◽  
Drug Concentrations ◽  
Significant Difference ◽  
Millipore Membrane ◽  
Total Concentrations

Abstract We compare a new ultrafiltration technique, involving a unique Millipore membrane, with the classical method of equilibrium dialysis for determining the fraction of thiopental not bound to serum proteins. This fraction, as determined by equilibrium dialysis at 37 degrees C, ranged between 12 and 16% for total concentrations at 50 microgram/L to 10 mg/L of serum. In contrast, ultrafiltration at 37 degrees C yielded a 49% higher value for unbound thiopental: 26.3 (SD 2.6)%. Determined at room temperature (24 degrees C), there was no statistically significant difference for results by the two methods: 14.2 and 15.9%, respectively. The discrepancy between results at 37 degrees C may partly be explained by serum proteins penetrating the Ultra-Free filter. For the routine clinical measurement of unbound drug concentrations, the ultrafiltration membrane at room temperature appears to be sufficiently accurate and less time-consuming than equilibrium dialysis.

Binding of labeled thyroxin analog to serum proteins evaluated after radioimmunoassay of free thyroxin.

1989 ◽  
Vol 35 (3) ◽  
pp. 475-477 ◽  
Author(s):  
G Arevalo
Keyword(s):  
Serum Proteins ◽  
Equilibrium Dialysis ◽  
Normal Serum ◽  
Thyroid Status ◽  
Nonthyroidal Illness ◽  
Serum Pool ◽  
Normal Individuals ◽  
Ambulatory Patients ◽  
One Step

Abstract In ambulatory patients, assay of free thyroxin (FT4) in serum correlates well with thyroid status and with results obtained by equilibrium dialysis. The validity of FT4 results has been questioned mainly in euthyroid patients with altered concentrations of thyroid hormone-binding proteins, as in nonthyroidal illness, hereditary analbuminemia, familial dysalbuminemic hyperthyroxinemia (FDH), and the presence of iodothyronine-binding antibodies. I present here a study of the binding of [125I]T4-derivative to serum proteins in the supernate, which is ordinarily discarded after determination of FT4 by one-step radioimmunoassay with dextran-coated charcoal used to separate the free and bound fractions. The results are expressed as a ratio, with results for a normal serum pool as reference. The average ratio was high in hyperthyroid subjects, 1.26 (SD 0.12, n = 25), and in hypoalbuminemia, 1.20 (SD 0.10, n = 15), and low in FDH, 0.62 (SD 0.11, n = 9), and hypothyroid subjects, 0.90 (SD 0.06, n = 20). In normal individuals it was 0.98 (SD 0.05, n = 30). Determination of the analog-binding rate complements the FT4 result and allows for the recognition of cases with abnormal binding by serum proteins, without recourse to other tests recommended for thyroid-function studies.

Simple Manual Procedure for Determination of Serum Triglycerides

1975 ◽  
Vol 21 (6) ◽  
pp. 768-770 ◽  
Author(s):  
Jose Mendez ◽  
Barry Franklin ◽  
Harry Gahagan
Keyword(s):  
Quality Control ◽  
Calibration Curve ◽  
Room Temperature ◽  
Extraction Procedure ◽  
Serum Triglycerides ◽  
Modified Method ◽  
Color Development ◽  
Significant Difference ◽  
Control Samples

Abstract We describe a modified method for determining serum triglycerides (triacylglycerols), which is based on the heptane extraction procedure of Gottfried and Rosenberg [Clin. Chem. 19, 1077 (1973)] with the stable saponification, oxidation, and color development reagents of Neri and Frings [Clin. Chem. 19, 1201 (1973)]. This modified method eliminates one heating step, reduces saponification time to 5 min, absorbances are read at room temperature, and the calibration curve is linear to 3.0 g/liter. A sample comparison between the proposed method and the automated Block and Jarrett [Am. J. Med. Technol. 35, 1 (1969)] procedure showed no significant difference (r = 0.98). The coefficient of variation (47 duplicate samples) for the modified method was 6.3%. Further validation was obtained from analysis of quality-control samples; the proposed method gave equivalent values.

scholarly journals Greener Analytical Method for Determination of Iodine Number of Edible Oils

2020 ◽  
Vol 9 (6) ◽  
pp. 36
Author(s):  
Thidarat Kruatian ◽  
Kritsana Jitmanee
Keyword(s):  
Iodine Number ◽  
Standard Method ◽  
Analytical Method ◽  
Present Method ◽  
Edible Oils ◽  
Classical Method ◽  
Sample Weight ◽  
Number Range ◽  
Significant Difference

A greener analytical method for determination of iodine number (IN) of oils is presented. As per the AOAC standard method, a large amount of solvent and reagent was used, and long incubation time was required. This research is aimed at using less amount of solvent and reagent, less sample weight, and shorten the analysis time by using the modified titrimetric AOAC standard method. The study showed that by reducing the sample size, the amount of reagent could be decreased to 1.00 mL and the reaction time of 1 min is enough for completion of the reaction. The amount of reagent used was at least 25 times less than that of the classical method. There was no significant difference at 95% confidence level between the results obtained by the proposed method and the standard method, and both results correlated well. The present method can be applied to edible oils commonly found in the market (iodine number range of 6.0 to 130).

Simplified Technic for the Determination of Serum Protein-Bound Iodine

1961 ◽  
Vol 7 (6) ◽  
pp. 637-645 ◽  
Author(s):  
Louise W Faulkner ◽  
Richard P Levy ◽  
Jack R Leonards
Keyword(s):  
Serum Protein ◽  
Sodium Carbonate ◽  
Room Temperature ◽  
Sodium Carbonate Solution ◽  
Serum Proteins ◽  
Internal Standard ◽  
Temperature Correction ◽  
Carbonate Solution ◽  
Correction Formula

Abstract A simplified technic for the determination of serum protein-bound iodine (PBI) is presented. Endogenously labeled l131 PBI is completely recovered. The technic is based on the method of Barker et al. (1) and includes the following modifications: The number of washes of the precipitated serum proteins are decreased. Unashed iodide standards are used in a sodium carbonate solution rather than an internal standard. A temperature-correction formula is employed to allow the cericarsenite-iodide reaction to be carried out at room temperature, and a stable cerate color is produced with brucine sulfate so that the colorimetry is carried out with greater convenience. The serum PBI concentrations are read directly from a graph, which simplifies the calculations.

scholarly journals New Fluorometric Method for the Determination of Ketotifen Fumarate Using Continuous Flow Injection Analysis via ISNAG-fluorimeter

2019 ◽  
Vol 16 (2) ◽  
pp. 0353
Author(s):  
Turkie Et al.
Keyword(s):  
Flow Injection ◽  
Limit Of Detection ◽  
Classical Method ◽  
Calibration Graph ◽  
Injection System ◽  
Minimum Concentration ◽  
Ketotifen Fumarate ◽  
Fluorescence Measurements ◽  
Significant Difference

        A newly developed analytical method was conducted for the determination of Ketotifen fumarate (KTF) in pharmaceuticals drugs via quenching of continuous fluorescence of 9(10H)-Acridone (ACD). The method was applied using flow injection system of a new homemade ISNAG fluorimeter with fluorescence measurements at ± 90◦ via 2×4 solar cell. The calibration graph was linear in the range of 1-45 mmol/L, with correlation coefficient r = 0.9762 and the limit of detection 29.785 µg/sample from the stepwise dilution for the minimum concentration in the linear dynamic ranged of the calibration graph. The method was successfully applied to the determination of Ketotifen fumarate in two different pharmaceutical drugs. A comparison was made between the newly developed method analysis and the classical method using the standard addition method via the use of individual and paired t-test and F-test. It was noticed that there was no significant difference between the two methods at 95 % confidence level.

scholarly journals Determination of reducing and total sugars in West Indian cherry (malpighia punicifolia, L.) juice

1969 ◽  
Vol 37 (3) ◽  
pp. 199-205
Author(s):  
Rafael Santini, Jr.
Keyword(s):  
Ascorbic Acid ◽  
Room Temperature ◽  
Reducing Sugars ◽  
Sugar Content ◽  
West Indian ◽  
Total Sugars ◽  
Total Sugar Content ◽  
Significant Difference ◽  
Cherry Juice

(1) Ascorbic acid is the substance responsible for the discrepancies found in the determination of reducing sugars and total sugars by the Lane-Eynon method. By correcting for ascorbic acid using the factor (F) 0.686, the discrepancy is eliminated and the Lane-Eynon method can be used. (2) To determine the total sugar content of West Indian cherry juice corrected reducing sugars only need be assayed, because it was proved experimentally and statistically that there is no significant difference between corrected reducing and corrected total sugars. (3) The sugar content of West Indian cherry juices stored at room temperature and at 45°F. does not change appreciably after 1 year. (4) At 45°F. ascorbic acid is lost less readily than at room temperature, but temperature produces no significant difference in the true sugar content of the juice.

scholarly journals A kinetic spectrophotometric method for the determination of lansoprazole in pharmaceutical formulations

2006 ◽  
Vol 71 (10) ◽  
pp. 1107-1120 ◽  
Author(s):  
Nafisur Rahman ◽  
Zehra Bano ◽  
Hejaz Azmi ◽  
Mohammad Kashif
Keyword(s):  
Spectrophotometric Method ◽  
Room Temperature ◽  
Pharmaceutical Formulations ◽  
Accuracy And Precision ◽  
Significant Difference ◽  
Kinetic Spectrophotometric ◽  
Comparison Of The Results ◽  
Calibration Equations ◽  
Method Show

Asimple kinetic spectrophotometric method has been developed for the determination of lansoprazole in pharmaceutical formulations. The method is based on the oxidation of the drug with alkaline potassium permanganate at room temperature. The reaction was followed spectrophotometrically by measuring the increase in the absorbance owing to the formation of MnO 42? at 610 nm (Method A) and the decrease in the absorbance at 530 nm due to the disapperance of MnO4? (Method B). Calibration procedures were adopted for the assay of the drug. The calibration curves were linear over the concentration ranges of 5-150 and 5-70?g ml-1, with the corresponding calibration Equations: rate = -3.915x10-6 + 5.271x10-5 c and ?A = 1.04x 10-3 + 1.78x10-3 c for methods A, and B, respectively. A statistical comparison of the results of the proposed procedures with those of the reference spectrophotometric method show excellent agreement and indicated no significant difference between the compared methods in terms of accuracy and precision. Interval hypothesis tests were also performed, which indicated that the true bias of all samples was less than ? 2 %. .

Comparison of blood serum protein analysis by MALDI-MS from either conventional frozen samples or storage disc-deposited samples: A study with human serum from pregnant donors and from patients with intrauterine growth restriction

2018 ◽  
Vol 25 (4) ◽  
pp. 381-390
Author(s):  
Manja Wölter ◽  
Manuela Russ ◽  
Charles A Okai ◽  
Werner Rath ◽  
Ulrich Pecks ◽  
...  
Keyword(s):  
Intrauterine Growth Restriction ◽  
Room Temperature ◽  
Serum Proteins ◽  
Protein Analysis ◽  
Mass Spectrometric ◽  
Growth Restriction ◽  
Intact Protein ◽  
Protein Abundance ◽  
Intrauterine Growth

Mass spectrometric profiling of intact serum proteins, i.e. determination of relative protein abundance differences, was performed using two different serum sample preparation methods: one with frozen and thawed serum, the other with at room temperature deposited and dried serum. Since in a typical clinical setting freezing of serum is difficult to achieve, sampling at room temperature is preferred and can be met when using the Noviplex™ card system. Once deposited and dried, serum proteins can be stored and shipped at room temperature. After resolubilization of serum proteins from “dried serum spots”, mass spectra of high quality have been recorded comparable to those that were obtained using fresh-frozen and subsequently thawed serum samples. Differentiation between patients with intrauterine growth restriction and control individuals was achievable, independent from the sample work-up procedure. Having at hand a reliable and robust method for serum storage and shipment which works at room temperature bridges the gap between the clinics and the protein analysis laboratory. Our novel serum handling protocol reduces costs for both, storage and shipping, and ultimately enables clinical risk assessment based on mass spectrometric determination of intact protein abundance profiles.

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