An enzymic assay for the specific determination of methanol in serum.

1987 ◽  
Vol 33 (12) ◽  
pp. 2204-2208 ◽  
Author(s):  
B Vinet
Keyword(s):  
Clinical Chemistry ◽  
Alcohol Oxidase ◽  
Chemistry Laboratory ◽  
Enzymatic Method ◽  
Specific Determination ◽  
Reaction Proceeds ◽  
Clinical Chemistry Laboratory ◽  
Enzymic Assay ◽  
True Values

Abstract This method for the specific determination of methanol in serum is based on the following two reactions: (formula; see text) Alcohol oxidase is not specific: it converts all lower alcohols to their corresponding aldehydes; however, formaldehyde dehydrogenase is specific and thus the transformation of NAD+ to NADH (which is used to monitor the reaction) proceeds only if methanol is originally present in the sample. The method was automated with a Roche COBAS FARA centrifugal analyzer. The calibration curve is linear between 0.6 and 12 mmol/L. The detection limit is about 0.6 mmol/L. The CV is 4.6% for a concentration of 3 mmol/L. When 55 serum specimens known to be free of methanol were supplemented with known amounts of methanol and analyzed by the enzymatic method, the results correlated well (r = 0.987) with the true values, the regression equation being: y = 1.016x + 0.661, where x represents the true values. Results are not affected by other alcohols that may be present in serum, by methanol metabolites, or by some commonly prescribed drugs. The major advantage of this new assay is that it can be used 24 h a day in any clinical chemistry laboratory.

Quantitative Identification of Urinary Calculi

1955 ◽  
Vol 1 (4) ◽  
pp. 241-248 ◽  
Author(s):  
Reid H Leonard ◽  
Arthur J Butt
Keyword(s):  
Oxalic Acid ◽  
Quantitative Determination ◽  
Clinical Chemistry ◽  
Urinary Calculi ◽  
Ammonia Nitrogen ◽  
Chemistry Laboratory ◽  
Calcium Phosphorus ◽  
Clinical Chemistry Laboratory ◽  
Quantitative Identification

Abstract Quantitative determination of calcium, phosphorus, and oxalic acid, assisted by occasional determination of ammonia nitrogen and insoluble nitrogen when indicated by qualitative tests, provides a means of computing the component substances of calculi. The determinations may be performed by slight modifications of the methods in use in the routine clinical chemistry laboratory, although flame photometry is particularly convenient for the determination of calcium.

Simultaneous Measurement of Diphenylhydantoin and Primidone in Serum by Gas—Liquid Chromatography

1970 ◽  
Vol 16 (2) ◽  
pp. 107-110 ◽  
Author(s):  
M A Evenson ◽  
P Jones ◽  
B Darcey
Keyword(s):  
Liquid Chromatography ◽  
Clinical Chemistry ◽  
Chemistry Laboratory ◽  
Specific Method ◽  
Gas Liquid Chromatography ◽  
Serum Samples ◽  
Large Numbers ◽  
Clinical Chemistry Laboratory ◽  
Isothermal Gas

Abstract The need for simultaneous determination of the concentration of diphenylhydantoin (Dilantin) and primidone (Mysoline) in serum is frequently expressed to the clinical chemistry laboratory. Isothermal gas-liquid chromatography (GLC) has been used to develop a rapid, specific method. The method involves a single extraction and no derivative formation. The procedure is simple enough to be used with large numbers of samples. Detection limits for the method are 0.3 µg diphenylhydantoin per ml and 0.1 µg primidone per ml. The mean precision of the method is 6.2% and 4.8%, expressed as the coefficient of variation, for diphenylhydantoin and primidone, respectively. Barbiturates and glutethimide added to serum samples did not interfere with the analysis. The method has been used for more than 500 patients without interferences from metabolites, and meets all criteria for routine and emergency use.

Feasibility of Multiple Simultaneous Enzyme Assays, for Diagnostic Purposes, with the GeMSAEC Fast Analyzer

1971 ◽  
Vol 17 (8) ◽  
pp. 715-720 ◽  
Author(s):  
Thomas O Tiffany ◽  
George F Johnson ◽  
Max E Chilcote
Keyword(s):  
Large Scale ◽  
Experimental Approach ◽  
Clinical Chemistry ◽  
Chemistry Laboratory ◽  
Large Numbers ◽  
Coefficients Of Variation ◽  
Clinical Chemistry Laboratory ◽  
Analytical Variation ◽  
Instrumental Precision

Abstract The GeMSAEC fast analyzer provides the clinical chemistry laboratory with an analytical instrument that can be used to perform large numbers of kinetic enzyme analyses. Precise enzyme-rate analyses can be done routinely, on a large scale, and at a decreased cost per test. Improved precision in analyses of enzymes should provide more reliable data because analytical variation is lessened. We have asked how the fast analyzer might provide more useful diagnostic information to the clinician. We have selected the ratio of SGOT to SGPT activity in serum as an example, and examined instrumental precision. The coefficients of variation of the ratio, determined in the range of 50 and 140 Karmen units (which represents slightly elevated to clearly elevated values), are 4.8% and 2.2%, respectively. We examined the feasibility of measuring two or more enzyme activities simultaneously in one sample, to produce a diagnostic enzyme profile. Determination of SGOT, SGPT, and GLDH in parallel is presented as an example. In addition, we illustrate spectrophotometric linearity at 340 nm and discuss instrumental noise and an experimental approach to determining it by use of a premix experiment.

Determination of Calcium and Magnesium in Serum, Urine, Diet, and Stool by Atomic Absorption Spectrophotometry

1967 ◽  
Vol 13 (3) ◽  
pp. 204-214 ◽  
Author(s):  
Elizabeth G Gimblet ◽  
Amy F Marney ◽  
Roy W Bonsnes
Keyword(s):  
Atomic Absorption ◽  
Clinical Chemistry ◽  
Atomic Absorption Spectrophotometry ◽  
Chemistry Laboratory ◽  
Absorption Spectrophotometry ◽  
Clinical Chemistry Laboratory ◽  
Calcium And Magnesium

Abstract Atomic absorption spectrophotometry was evaluated as a method for the determination of calcium and magnesium in serum, urine, diet, and stool, and was found a most suitable technic for a large clinical chemistry laboratory.

Automated development of a kinetic method for the continuous-flow determination of creatinine.

1978 ◽  
Vol 24 (12) ◽  
pp. 2115-2124 ◽  
Author(s):  
A S Olansky ◽  
S N Deming
Keyword(s):  
Continuous Flow ◽  
Clinical Chemistry ◽  
Kinetic Method ◽  
Chemistry Laboratory ◽  
Chemical Methods ◽  
Central Composite Experimental Design ◽  
Clinical Chemistry Laboratory ◽  
Computer Controlled ◽  
Central Composite

Abstract A "stopped-flow" method for the kinetic Jaffé determination of creatinine was developed, with the use of a computer-controlled continuous-flow system. Simplex optimization was used to find conditions of hydroxide and picrate giving maximum sensitivity for creatinine. We used a modified central composite experimental design to evaluate creatinine sensitivity and albumin, glucose, and acetone interferences as functions of hydroxide and picrate concentrations. More importantly, this work illustrates that the automated development of clinical chemical methods offers an efficient means of obtaining optimized, well-understood analytical procedures for subsequent routine use in the clinical chemistry laboratory.

Rapid System of Microchemical Analysis for the Clinical Laboratory

1958 ◽  
Vol 4 (2) ◽  
pp. 127-141 ◽  
Author(s):  
Abraham Saifer ◽  
Shirley Gerstenfeld ◽  
Michael C Zymaris
Keyword(s):  
Clinical Laboratory ◽  
Clinical Chemistry ◽  
Chemistry Laboratory ◽  
Alkaline Phosphatases ◽  
Microchemical Analysis ◽  
Clinical Chemistry Laboratory ◽  
Semiautomatic System ◽  
Sodium And Potassium ◽  
Nitrogen Phosphorus

Abstract A rapid, semiautomatic system of microchemical analysis for the clinical chemistry laboratory has been proposed. Five basic elements of this system are: (1) The use of siliconated-heparinized plasma. (2) The use of the calibrated-pipet-tip buret technic for measuring small (0.10-ml.) samples. (3) The use of the decantation principle as a precision step in making quantitative transfers. (4) The use of automatic syringe pipets for adding constant volumes of reagents, (5) The use of specific enzymatic methods, whenever these are applicable, for the determination of biologic constituents. The analytic system has already been applied to the determination of such important biologic constituents as glucose, urea nitrogen, phosphorus, acid and alkaline phosphatases, sodium and potassium, calcium, and total protein. The semiautomatic system permits the use of microprocedures in a clinical chemistry laboratory by persons of limited technical skill.

Total homocysteine in plasma or serum: methods and clinical applications

1993 ◽  
Vol 39 (9) ◽  
pp. 1764-1779 ◽  
Author(s):  
P M Ueland ◽  
H Refsum ◽  
S P Stabler ◽  
M R Malinow ◽  
A Andersson ◽  
...  
Keyword(s):  
Room Temperature ◽  
Clinical Chemistry ◽  
Continuous Production ◽  
Single Species ◽  
Clinical Applications ◽  
Chemistry Laboratory ◽  
Clinical Chemistry Laboratory ◽  
Total Homocysteine

Abstract Total homocysteine is defined as the sum of all homocysteine species in plasma/serum, including free and protein-bound forms. In the present review, we compare and evaluate several techniques for the determination of total homocysteine. Because these assays include the conversion of all forms into a single species by reduction, the redistribution between free and protein-bound homocysteine through disulfide interchange does not affect the results, and total homocysteine can be measured in stored samples. Total homocysteine in whole blood increases at room temperature because of a continuous production and release of homocysteine from blood cells, but artificial increase is low if the blood sample is centrifuged within 1 h of collection or placed on ice. Different methods correlate well, and values between 5 and 15 mumol/L in fasting subjects are considered normal. Total homocysteine in serum/plasma is increased markedly in patients with cobalamin or folate deficiency, and decreases only when they are treated with the deficient vitamin. Total homocysteine is therefore of value for the diagnosis and follow-up of these deficiency states and may compensate for weaknesses of the traditional laboratory tests. In addition, total homocysteine is an independent risk factor for premature cardiovascular diseases. These disorders justify introduction of the total homocysteine assay in the routine clinical chemistry laboratory.

Occult causes of hypokalemia.

1984 ◽  
Vol 30 (8) ◽  
pp. 1406-1408 ◽  
Author(s):  
R N Walmsley ◽  
G H White
Keyword(s):  
Clinical Picture ◽  
Clinical Investigation ◽  
Clinical Chemistry ◽  
Definitive Diagnosis ◽  
Chemistry Laboratory ◽  
Clinical Investigations ◽  
Urinary Potassium ◽  
Plasma Electrolytes ◽  
Clinical Chemistry Laboratory

Abstract Most causes of hypokalemia are obvious from the clinical picture and the values for plasma electrolytes. In cases with obscure etiology, a pretreatment estimation of urinary potassium and chloride often helps lead the clinician into new and fruitful avenues of clinical investigation. Here we present four cases of hypokalemia in which the pathogenesis was initially enigmatic but was clarified somewhat by the determination of the urinary electrolytes. These simple, inexpensive investigations were initiated by the clinical chemistry laboratory in each case. The results encouraged the physicians to consider further clinical investigations, which led to a definitive diagnosis, before invoking expensive hormonal analyses.

scholarly journals FT-IR Analysis of Urinary Stones: A Helpful Tool for Clinician Comparison with the Chemical Spot Test

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Aniello Primiano ◽  
Silvia Persichilli ◽  
Giovanni Gambaro ◽  
Pietro Manuel Ferraro ◽  
Alessandro D’Addessi ◽  
...  
Keyword(s):  
Kidney Stones ◽  
Clinical Chemistry ◽  
Urinary Calculi ◽  
Spot Test ◽  
Chemistry Laboratory ◽  
Urinary Stones ◽  
Clinical Chemistry Laboratory ◽  
Ft Ir ◽  
Ir Analysis

Background.Kidney stones are a common illness with multifactorial etiopathogenesis. The determination of crystalline and molecular composition and the quantification of all stone components are important to establish the etiology of stones disease but it is often laborious to obtain using the chemical method. The aim of this paper is to compare chemical spot test with FT-IR spectroscopy, for a possible introduction in our laboratory.Methods.We analyzed 48 calculi using Urinary Calculi Analysis kit in accordance with the manufacturer’s instructions. The same samples were analyzed by FT-IR using the Perkin Elmer Spectrum One FT-IR Spectrometer. All FT-IR spectra of kidney stones were then computer matched against a library of spectra to generate a report on the various components.Results.On the basis of FT-IR analysis, the 48 calculi were divided into three groups: pure stone, mixed stone, and pure stone with substances in trace. Results of each group were compared with those obtained with chemical spot test. A general disagreement between methods was observed.Conclusions.According to our data, the introduction of the FT-IR technique in clinical chemistry laboratory may be more responsive to clinician expectations.

Sign in / Sign up

Export Citation Format

Share Document