Beckman Coulter UniCel DxC 600, Instructions For Use Manual

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A13914AF
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System Description
Cartridge Chemistry: Principles of Measurement
Cartridge Chemistry: Principles of Measurement
Spectrophotometric Methods
Spectrophotometric methods rely on the principle that a sample, such as a patient sample, a
control, or a calibrator, when mixed with one or more appropriate chemical reagents, produces a
substance that has the ability to absorb light at specific wavelengths. This substance is referred to
as a
chromophore .
Beer's Law
According to Beer's Law, the amount of light absorbed by the chromophore is proportional to the
concentration of the constituent being measured. The system can measure this as an endpoint or a
rate of formation.
Table 1.19 Methodology and Modules Used with Modular Chemistries
Chemistry Methodology Module
Sodium Ion selective electrode (ISE) ISE Flow cell
Potassium Ion selective electrode ISE Flow cell
Chloride Ion selective electrode ISE Flow cell
Carbon Dioxide pH electrode ISE Flow cell
Calcium Ion selective electrode ISE Flow cell
Urea Nitrogen
a
a. DxC 800 only.
Conductivity electrode Urea Nitrogen
Phosphorus
a
Colorimetric Phosphorus
Creatinine
a
Colorimetric Creatinine
Glucose Oxygen sensor Glucose
Total Protein
a Colorimetric Total Protein
Albumin
a Colorimetric Albumin
A = abc
where
A = absorbance of the chromophore
a = absorptivity of the absorbing substance at the specific measuring wavelength(s)
b = cuvette light pathlength (cm)
c = constituent concentration (M)