Automated enzymic determination of ethanol in blood, serum, and urine with a miniature centrifugal analyzer.

1976 ◽  
Vol 22 (6) ◽  
pp. 802-805 ◽  
Author(s):  
T P Hadjiioannou ◽  
S I Hadjiioannou ◽  
J Avery ◽  
H V Malmstadt
Keyword(s):  
Blood Serum ◽  
Reaction Rates ◽  
Rate Of Change ◽  
Coefficients Of Variation ◽  
Analytical Recovery ◽  
Rate Method ◽  
Relative Errors ◽  
Urine Specimens ◽  
Serum And Urine

Abstract We describe an automated spectrophotometric reaction-rate method for determination of ethanol in serum and urine with a miniature centrifugal analyzer. The theanol is selectively oxidized in the presence of alcochol dehydrogenase and NAD+ to form NADH, which is measured by the rate of change of its absorbance. Reaction rates are determined automatically, and unknown concentrations are calculated from a computer-generated working curve based on aqueous ethanol standards. Blood, serum, or urine specimens need not be deproteinized. The method permits duplicate analysis of at least 30 samples per hour. Coefficients of variation and relative errors are about 2-3% for ethanol concentrations of 0.3-3.0 mug per 2 mul of sample. Analytical recovery of ethanol added to serum is 92-103% (average, 98.5%). Comparisons with distillation-oxidation, gas-chromatographic, and conventional enzymic procedures give satisfactory agreement.

Automated Enzymatic Determination of L-Lactate in Serum, with Use of a Miniature Centrifugal Anlyzer

1976 ◽  
Vol 22 (12) ◽  
pp. 2038-2041 ◽  
Author(s):  
T P Hadjiioannou ◽  
S I Hadjiioannou ◽  
S D Brunk ◽  
H V Malmstadt
Keyword(s):  
Lactate Dehydrogenase ◽  
Reaction Rate ◽  
Enzymatic Reaction ◽  
Reaction Rates ◽  
Enzymatic Determination ◽  
Analytical Recovery ◽  
Rate Method ◽  
Relative Errors ◽  
Lithium Lactate

Abstract We describe an automated enzymatic reaction-rate method for spectrophotometric determination of lactate in serum with a miniature centrifugal analyzer. The L(+)-lactate is selectively oxidized in the presence of lactate dehydrogenase (EC 1.1.1.27) and NAD+ to from NADH, whitch is measured from its absorption. Reaction rates are determined automatically, and unknown concentrations are calculated from a computer0generated calibration curve with aqueous lithium lactate standards. Lactte concentrations in the range 0.32-1.6 µg/4 µl (80-400 mg/liter) of sample were determined with relative errors and coefficient of variation of 4.8%. Analytical recovery of lactate added to pooled serum was 89-112% (average, 101%). Comparison with a kit ("Rapid Lactate") method gave a correlation coefficient squared of 0.979 over a concentration range of 39-779 mg/liter.

Micromethod for determination of creatinine in biological fluids by high-performance liquid chromatography.

1978 ◽  
Vol 24 (5) ◽  
pp. 747-750 ◽  
Author(s):  
S J Soldin ◽  
J G Hill
Keyword(s):  
High Performance Liquid Chromatography ◽  
Continuous Flow ◽  
Present Method ◽  
High Performance ◽  
Biological Fluids ◽  
Coefficients Of Variation ◽  
Analytical Recovery ◽  
Urine Specimens ◽  
Serum And Urine

Abstract We describe a procedure for the rapid and specific measurement of creatinine, in which it is separated from other compounds in serum or urine by paired-ion chromatography and is quantified by measuring its absorbance at 200 nm. The procedure can be done on as little as 10 microliter of serum. Between-day precision studies for concentrations of 13 and 62 mg/liter yielded coefficients of variation of 6.9 and 2.2%, respectively. Analytical recovery of various amounts of creatinine added to plasma exceeded 95% in all cases. The proposed procedure was compared with the continuous-flow procedure by analyzing a series of serum and urine specimens by both methods. There was excellent agreement for urine specimens, but with serum the results by the present method were significantly (P less than 0.001) lower.

Automated enzymatic determination of L-lactate in serum, with use of a miniature centrifugal analyzer.

1976 ◽  
Vol 22 (12) ◽  
pp. 2042-2045 ◽  
Author(s):  
T P Hadjiioannou ◽  
S I Hadjiioannou ◽  
S D Brunk ◽  
H V Malmstadt
Keyword(s):  
Lactate Dehydrogenase ◽  
Reaction Rate ◽  
Enzymatic Reaction ◽  
Reaction Rates ◽  
Enzymatic Determination ◽  
Analytical Recovery ◽  
Rate Method ◽  
Relative Errors ◽  
Lithium Lactate

Abstract We describe an automated enzymatic reaction-rate method for spectrophotometric determination of lactate in serum with a miniature centrifugal analyzer. The L(+) -lactate is selectively oxidized in the presence of lactate dehydrogenase (EC 1.1.1.27) and NAD+ to form NADH, which is measured from its absorption. Reaction rates are determined automatically, and unknown concentrations are calculated from a computer-generated calibration curve with aqueous lithium lactate standards. Lactate concentrations in the range 0.32-1.6 mug/4 mul (80-400 mg/liter) of sample were determined with relative errors and coefficient of variation of 4.8%. Analytical recovery of lactate added to pooled serum was 89-112% (average, 101%). Comparison with a kit ("Rapid Lactate") method gave a correlation coefficient squared of 0.979 over a concentration range of 39-779 mg/liter.

Specific Enzymatic Determination of Glucose in Blood Serum or Plasma by an Automatic Potentiometric Reaction-Rate Method

1962 ◽  
Vol 8 (6) ◽  
pp. 606-615 ◽  
Author(s):  
H V Malmstadt ◽  
H L Pardue
Keyword(s):  
Blood Serum ◽  
Blood Plasma ◽  
Reaction Rate ◽  
Measurement Time ◽  
Sample Handling ◽  
Enzymatic Determination ◽  
Speed Up ◽  
Rate Method ◽  
Relative Errors

Abstract A new automatic potentiometric reaction-rate method has been applied to the specific enzymatic measurement of glucose in blood plasma or serum. A new filtering technic is described for removal of precipitated protein. The use of injection pipets to simplify and speed up the reagent-and sample-handling step is described. Glucose is determined in 0.02 ml. of serum or plasma with relative errors within 2%. The average measurement time is about 30 sec.

Immunonephelometric determination of retinol-binding protein in serum and urine.

1983 ◽  
Vol 29 (5) ◽  
pp. 853-856 ◽  
Author(s):  
M T Parviainen ◽  
P Ylitalo
Keyword(s):  
Binding Protein ◽  
Retinol Binding Protein ◽  
Good Precision ◽  
Serum Samples ◽  
Detection Range ◽  
Analytical Recovery ◽  
Beta 2 Microglobulin ◽  
Urine Specimens ◽  
Serum And Urine

Abstract An immunonephelometric method developed for measurement of retinol-binding protein (RBP) in serum and urine can detect it in concentrations of about 30 micrograms/L, which is in the lower limit of its normal concentration in urine (range 0-0.56 mg/L; mean +/- SD 0.19 +/- 0.15; n = 44). Urinary RBP was increased (range 0.93-29.5 mg/L) in all of 25 urine specimens from 13 subjects being treated with aminoglycoside (tobramycin). Urinary excretion of RBP was correlated (r = 0.83) with the excretion of beta 2-microglobulin. The within-assay and day-to-day precision (CV) was determined over the detection range of 0.03-8 mg/L. Within these limits the corresponding CVs varied from 4 to 27% and from 8 to 30%, respectively. The method had fairly good precision within the optimal measuring range of approximately 0.4 to 4.5 mg/L for both urine and 20-fold diluted serum samples. For various RBP concentrations our analytical recovery was 89-114% of added RBP. Results by this method correlated well (r = 0.96, n = 24) with those by a radial immunodiffusion method.

Rapid, simple enzymatic assay of free L-fucose in serum and urine, and its use as a marker for cancer, cirrhosis, and gastric ulcers

1990 ◽  
Vol 36 (3) ◽  
pp. 474-476 ◽  
Author(s):  
T Sakai ◽  
K Yamamoto ◽  
H Yokota ◽  
K Hakozaki-Usui ◽  
F Hino ◽  
...  
Keyword(s):  
Cancer Patients ◽  
Mass Screening ◽  
Healthy Subjects ◽  
Enzymatic Assay ◽  
Cirrhosis Of The Liver ◽  
Gastric Ulcers ◽  
Coefficients Of Variation ◽  
Analytical Recovery ◽  
Urine Specimens ◽  
Serum And Urine

Abstract We devised a kit for use with automated analyzers, for assay of urinary free L-fucose by means of a newly isolated L-fucose dehydrogenase (EC 1.1.1.122), and we measured L-fucose in healthy subjects, cancer patients, and patients with other diseases. It takes 10 min to complete one assay. Absorbance and L-fucose concentration were linearly related up to at least 3.0 mmol/L, analytical recovery was 90-104%, and intra- and interassay coefficients of variation were less than 4.2% and 7.8%, respectively. The concentrations of L-fucose, corrected for creatinine, were significantly higher than those in healthy subjects in nine of 18 patients with gastric ulcers, 19 of 21 patients with cirrhosis of the liver, and 206 of 366 patients with some type of cancer, reflecting a changed L-fucose metabolism. Because urine specimens are analyzed and the test is rapid and inexpensive, this method may be suitable for mass screening for some kinds of cancer, cirrhosis, and gastric ulcers.

Reference Values of Serum and Urine Creatinine, and of Creatinine Clearance by a New Enzymatic Method

1992 ◽  
Vol 29 (5) ◽  
pp. 523-528 ◽  
Author(s):  
O Sugita ◽  
K Uchiyama ◽  
T Yamada ◽  
T Sato ◽  
M Okada ◽  
...  
Keyword(s):  
Creatinine Clearance ◽  
Reference Intervals ◽  
Japanese Children ◽  
Mean Values ◽  
Urine Creatinine ◽  
Coefficients Of Variation ◽  
Analytical Recovery ◽  
Enzymatic Procedure ◽  
Serum And Urine

A new, totally enzymatic procedure for the determination of creatinine in serum and urine, using creatinine amidohydrolase, creatine amidinohydrolase, sarcosine oxidase and formaldehyde dehydrogenase is described. The assay was adapted to a discontinuous analyser with each analysis requiring only 20 μL of serum or 3 μL of urine. Analytical recovery of creatinine in serum and urine averaged 100·6%. Within-run and between-run precision studies gave coefficients of variation of 1·1% and 1·8%, respectively, for a serum with mean values of 83 μmol/L (9·4 mg/L) creatinine. Creatinine concentrations in serum and urine were measured by this procedure, in Japanese children and adults. The reference intervals for serum creatinine concentrations in adults were 55–96 μmol/L (6·2–10·9 mg/L) in men and 40–66 μmol/L (4·5–7·5 mg/L) in women, and for urine, 9·46–19·01 mmol/day (1070–2150 mg/day) in men and 6·75–10·61 mmol/day (764–1200 mg/day) in women. The reference intervals of creatinine clearance were 88·0–176·4 mL/min in men and 75·7–173·0 mL/min in women.

Determination of creatinine in serum and urine by a rapid liquid-chromatographic method

1990 ◽  
Vol 36 (6) ◽  
pp. 830-836 ◽  
Author(s):  
R Paroni ◽  
C Arcelloni ◽  
I Fermo ◽  
P A Bonini
Keyword(s):  
Signal To Noise Ratio ◽  
Liquid Chromatographic Method ◽  
Analytical Recovery ◽  
Internal Standardization ◽  
Assay Precision ◽  
Fuller’S Earth ◽  
Liquid Chromatographic ◽  
Specific Evaluation ◽  
Serum And Urine

Abstract We describe an HPLC ion-pair procedure for rapid and specific evaluation of creatinine in serum and urine. We used a 15 cm X 4.6 mm ODS column with a 50/50 (by vol) mixture of sodium decanesulfonic acid (10 mmol/L, pH 3.2) and methanol and measured absorbance at 236 nm. Serum (100 microL) or 30-fold-diluted urine (100 microL) was added to 400 microL of acetone. After centrifugation, the supernates (300 microL) were dried, reconstituted with the mobile phase, and injected into the HPLC. Assay precision was tested for concentrations of 10, 29, and 130 mg/L and yielded, respectively, 3.1%, 2.1%, and 1.1% for within-day CV and 2.8%, 2.1%, and 2.2% for total CV. Analytical recovery was 102 (+/- 6.7%). Linearity was demonstrated in the 0-200 mg/L range for serum and 0-3.5 g/L range for urine (r greater than or equal to 0.999). The detection limit for creatinine (signal-to-noise ratio = 3) was 0.5 mg/L. We used cimetidine for internal standardization. Correlation was good between this procedure and the Jaffé kinetic, the enzymatic (creatinine amidohydrolase), and the Fuller's earth alkaline picrate methods.

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