Reduction of the interferences of biochemicals and hematocrit ratio on the determination of whole blood glucose using multiple screen-printed carbon electrode test strips

Abstract

A practical approach to reduce the interferences of biochemicals and hematocrit ratio (Hct%) in the determination of whole blood glucose using multiple screen-printed carbon electrode (SPCE) test strips is described. SPCE test strips with and without glucose oxidase [i.e., GOD(+)-SPCEs and GOD(-)-SPCEs] were used and the chronoamperometric currents of test glucose solutions with various spiked uric acid concentrations and Hct% were measured. By establishing the interference relationships between glucose concentrations and uric acid concentrations as well as Hct% values and with appropriate corrections, the whole blood glucose determinations could be made to be more accurate and comparable to those determined by the reference YSI method. Specifically, the use of the DeltaI value, i.e., the current difference between GOD(+)-SPCE and GOD(-)-SPCE measurements, would reduce most of the uric acid/biochemical interferences. An interpolation method was also established to correct for the glucose determinations with Hct% interferences. The Hct% corrections using the interpolation method are especially important and necessary for those blood samples with glucose concentrations higher than 110 mg dL(-1) and Hct% values lower than 35%. This approach should also be applicable to other biochemical determinations using similar electrochemical techniques.

Enzyme‐Based Glucose Sensor: From Invasive to Wearable Device

“…Because the International Federation of Clinical Chemistry and Laboratory Medicine recommends that the measured glucose concentration should correspond to that in the plasma, the glucometer converts the glucose concentration in capillary whole blood into the concentration in the plasma. By measuring the alternating current impedance, the glucometer estimates the hematocrit ratio and applies this ratio to accurately convert the glucose level in the whole blood to that in the plasma (Figure c) . Although the conversion factor increases the accuracy of the reported glucose level, glucose monitoring via a blood strip is still prone to errors (Figure d) …”

“…c) Amperometric responses of glucose sensor to glucose concentrations of 75.7 (a), 170.4 (b), 318.0 (c), and 462.0 mg dL −1 (d) at different hematocrit ratio. Reproduced with permission . Copyright 2007, Springer Nature.…”

Analysis of the Change in the Blood Concentration-Time Profile Caused by Complex Drug–Drug Interactions in the Liver Considering the Enterohepatic Circulation: Examining Whether the Inhibition Constants for Uptake, Metabolism, and Biliary Excretion Can be Recovered by the Analyses Using Physiologically Based Pharmacokinetic Modeling

“…Fifty virtual human subjects were generated using Monte Carlo simulation with a given frequency distribution (average, coefficient of variation [CV], and the shape of distribution) for the parameters of each hypothetical substrate. 23,24,[26][27][28][29] The average value for each parameter was used as its original value described in Table 1.…”

Urine test strip analysis, concentration range and its interpretations of the parameters

“…The urine reagent test strip is a paper with various pads impregnated with chemicals that react with the compounds present in urine producing a characteristic color change in a certain concentration. The reading of the results can often be done by comparing the color chart with the labels attached to the bottle after dipping for appropriate seconds [9].…”

“…The test may provide information on the status of carbohydrate metabolism, the acid-base balance of the body, kidney, and liver function, and urinary tract infection [8]. The manufacturers recommend the test strips to be stored in the original airtight container to maintain reagent reactivity and to obtain accurate results, urine collection, storage, and handling must be sterile and follow standard procedures [9]. The most common dipstick examination of urine involves screening for abnormal levels of urinary occult blood, bilirubin, urobilinogen, ketones, protein, nitrite, glucose, pH, specific gravity, leukocytes, ascorbic acid, microalbumin, creatinine, calcium and so on.…”