1ST DAY MTLE REVIEW

A system to monitor the analytical process and to detect errors that can affect accuracy and precision

quality control

closeness of the measured value to the true value

accuracy

ability of an analytical method to give

ability of an analytical method to maintain accuracy and precision over an extended period of time

reliability

ability of an analytical method to measure the smalletst concentration of the analyte of interest

sensitivity

ability of an analytical method to measure only analyte of interest

specificity

indicates the ability of the test to generate more true positive & few false negative results.

diagnostic sensitivity

indicates the ability of the test to generate more true negative & few false positiveresults.

diagnostic specificity

Involves the analyses of control samples together with the patient specimen and important for the daily monitoring of accuracy and precision of analytical methods

intralab qc

involves proficiency testing that periodically provide samples of unknown concentrations to participating clinical laboratories

Interlab Quality Control

A material of known composition available in highly purified form

standard

standard color

colorless

Material with physical and chemical properties closely resembling the test specimen and containing pre analyzed concentrations of the substances being measured

control

control color

yellow

types of QUALITY CONTROL CHART

Gaussian Curve Youden Twin Plot Shewhart Levey-Jennings Chart

ERRORS WHICH CAN BE OBSERVED IN LJ CHART

trend outlier shift

Comprehensive set of policies, procedures, and practices followed to ensure the laboratory’s results are RELIABLE

quality assurance

nm - Visible spectrum

400-700

nm - Ultraviolet region (UV)

<400

nm - Infrared region (IR)

>700

is transmitted via electromagnetic waves that are characterized by their frequency and wavelength

energy

is the number of vibrations of wave motion per second

frequency

It involves measurement of the light transmitted by a solution to determine the concentration of the light-absorbing substances in the solution

spectrometry

types of spectrometry

single and double beam spectrometry

It is the simplest type of absorption spectrometer. and It is designed to make one measurement at a time at one specified wavelength

single beam spectrophotometer

Is an instrument that splits the monochromatic light into two components - one beam passes through the sample, and the other through a reference solution or blank

double beam spectrophotometer

types of double beam spectrophotometer

double beam in space and time

w/2 photodetectors

double beam in space

w/1 photodetectors

double beam in time

PARTS OF THE SPECTROPHOTOMETER

light source entrance slit monochromator exit slit cuvette photodetector and meter

It provides polychromatic light and must generate sufficient radiant

energy or power to measure the analyte of interest

light source

2 Types of light source

continuum and line source

emits radiation that changes in intensity; widely used in the laboratory

continuum source

is the commonly used continuum light source in the visible and near infrared region

tungsten light bulb

is routinely used to provide UV radiation in analytic spectrometers

deuterium lamp