Analytical Techniques and Instrumentation Flashcards
designed to compensate for variations in intensity of the light source by SPLITTING the light beam from the lamp and directing one portion to a reference cuvette and the other to the sample cuvette
Double-Beam Spectrophotometry
beam splitter, 2 photodetectors
a. double-beam-in-space
b. double-beam-in-time
a. double-beam-in-space
chopper, 1 photodetector
a. double-beam-in-space
b. double-beam-in-time
b. double-beam-in-time
- principle: measurement of the amount of light emitted by excited molecules
- 1000x more sensitive than spectrophotometry
fluorometry
fluorometry advantages:
highly sensitive and specific
principle: measurement of light emission caused by a chemical, biochemical or electrochemical reactions and not by photo illumination
Luminometry
emission of light caused by oxidation of organic compounds catalyzed by an enzyme, metal, or hemin
chemiluminescence
involves the use of natural substrates
ex. luciferin (fireflies light)
bioluminescence
emission of light caused by a reaction generated electrochemically on the surface of an electrode
electrochemiluminescence
detection of scintillation (flashes of light) using a PM tube and counting of the electrical impulses
Scintillation counting
Crystal scintillation (gamma counter)
a. I-125, I-131
b. H-3, C-14
a. I-125, I-131
Liquid scintillation (beta counter)
a. I-125, I-131
b. H-3, C-14
b. H-3, C-14
measurement of the amount of light blocked
a. turbidimetry
b. nephelometry
a. turbidimetry
amount of light scattered by a suspension of particles (Ag-Ab complexes)
a. turbidimetry
b. nephelometry
b. nephelometry
fragmentation and ionization of molecules
applications: MALDI TOF MS, GCMS or HPLC-MS, Tandem MS, IDMS
Mass Spectrophotometry
non-destructive method for determining the structure of organic compounds, used in lipoprotein particle
nuclear magnetic resonance spectroscopy
pumps each spx in a batch through a system of CONTINUOUS tubing (ex. SMA, technicon)
Continuous flow
air bubbles
a. separating, cleaning media
b. mixing samples & reagents
a. separating, cleaning media
coiled tubing/ glass coils
a. separating, cleaning media
b. mixing samples & reagents
b. mixing samples & reagents
uses CENTRIFUGAL force to transfer liquids in separate cuvettes; capable of batch analysis (ex. Cobas-Bio)
Centrifugal Analysis
places each sample and accompanying reagents in separate containers; batch analysis, random access or stat capabilities (ex. Vitros, Beckman, Dupont ACA)
Discrete analysis
each spx in a batch enters the analytical process ONE AFTER ANOTHER, and each result or set of results emerges in the same order as the spx are entered
a. Sequential analysis
b. Parallel analysis
a. Sequential analysis
all spx are subjected to a series of analytical processes at the SAME TIME and in a PARALLEL fashion
a. Sequential analysis
b. Parallel analysis
b. Parallel analysis
many spx are grouped in the same analytical sessionl large number of spx in one run
(multiple samples, one test at a time)
a. batch analysis
b. random-access analysis
a. batch analysis
each spx is analyzed for a different selection of tests (multiple tests, one sample at a time)
a. batch analysis
b. random-access analysis
b. random-access analysis
requires the rgt to be in a unique container or format provided by the manufacturer
a. closed-system analyzer
b. open-system analyzer
a. closed-system analyzer
oprtr is able to change the parameters related to an analysis and prepare in-house rgts or use rgts from a variety of suppliers
a. closed-system analyzer
b. open-system analyzer
b. open-system analyzer
reduced TAT and connectivity (electronic documentation of testing)
POCT devices
most commonly used POCT
Blood Glucose Monitors
Mass Spectrophotometry:
gold standard for drugs
GC-MS
Mass Spectrophotometry:
proteomics, peptides, microbial identification
MALDI-TOF MS
Inborn Errors of Metabolism screening; aka MS/MS
Tandem MS
reference method for Non-protein Nitrogenous (NPN) compounds
IDMS
