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A Pembroke

Publications and source records attributed to A Pembroke.

9 recordsLinked to original sources
PubMed1992

Improving accuracy of glucose oxidase procedure for glucose determinations on discrete analyzers.

We describe a rapid kinetic glucose oxidase (EC 1.1.3.4) procedure for quantifying glucose. Glucose oxidase concentration was reduced from the more usual 20 kU/L to 4 kU/L, and pH was reduced from 7.0 to 6.6. Potassium ferrocyanide (20 mumol/L) and ascorbate oxidase (1 kU/L) were incorporated in the procedure. The assay results vary linearly with glucose concentration from 0 to 50 mmol/L and are unaffected by bilirubin concentrations less than or equal to 600 mumol/L, hemoglobin less than or equal to 12 g/L, Intralipid less than or equal to 4 g/L, urate less than or equal to 1 mmol/L, and ascorbate less than or equal to 2.0 mmol/L. The assay is readily adaptable to most open-system analyzers.

Ascorbic Acid↗
PubMed1992

A simplified procedure for eliminating the negative interference of bilirubin in the Jaffé reaction for creatinine.

The negative interference by bilirubin in the measurement of creatinine by the Jaffé procedure is well documented. We describe a procedure for the elimination of interfering bilirubin by oxidation to biliverdin through the addition of potassium ferricyanide before the alkaline picrate reagent. We detected no negative interference with the addition of as much as 600 mumol/L bilirubin. The procedure shows good agreement with a recently described blank rate method for analyzing icteric samples.

Bilirubin↗
PubMed1992

Single stable reagent (Arsenazo III) for optically robust measurement of calcium in serum and plasma.

We describe a method based on a single stable reagent for the determination of calcium in serum and plasma with use of Arsenazo III, 200 mumol/L in 50 mmol/L 1,4-piperazinediethanesulfonic acid (PIPES) buffer. The method showed significant positive interference in plasma at pH less than 6.6 because of the precipitation of fibrinogen, which was eliminated by increasing the pH to 6.8. The assay showed no interference from as much as 600 mumol of bilirubin and 12 g of hemoglobin per liter when applied in a simple monochromatic procedure at 660 nm. The standard curve for calcium was linear from 0 to 5.0 mmol/L. Addition of Intralipid at concentrations greater than 3 g/L demonstrated positive interference, which could be eliminated by using a 700-nm blanking wavelength. The procedure showed good agreement with all-method mean values from two external quality-control schemes.

Arsenazo III↗
PubMed1992

Measuring albumin and calcium in serum in a dual test with the Hitachi 704.

We describe a method for simultaneously determining albumin, by using bromcresol purple, and calcium, by using Arsenazo III, in the same analytical cuvette on the Hitachi 704. Both assays agree well with accepted procedures. The standard curves for the albumin and calcium assays are linear from 0 to 60 g/L and 0 to 5.0 mmol/L, respectively. Calibration is stable for 7 days with use of open reagent in the instrument. Both assays are unaffected by hemoglobin less than or equal to 5 g/L and Intralipid less than or equal to 4 g/L; calcium is unaffected by bilirubin less than or equal to 600 mumol/L.

Arsenazo III↗