Term
| Advantages of Color Assays |
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Definition
-Quick & Cheap
-homogenous
-useful in scene residue testing
-minimum equipment
-little sample prep
-quantitation done in a spectrophotometer |
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Term
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Definition
| readgent blank that does not contain analyte of interest |
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Term
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Definition
| sample that is known to have the analyte of interest |
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Term
| Disadvantages of color tests |
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Definition
sensitivity is limieted
only certain substances can be analyzed in this manner
prescence of other colored substances may invalidate |
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Term
| Spectrophotometry & Beer Lamber Law |
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Definition
When a compound is irradiated with electomagenetic radiation of an appropriate wavelent it will absorp energy
Factors affect Beer-Lambert
- Analyte Concentration
-interactions/ decompoistion
-instrumental
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Term
| Single Beam Spectrophotometer |
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Definition
AKA Colorimeters
Tungsten filament lamp
one beam of light-measured by a photo cell |
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Term
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Definition
split light into two paths
one beam serves as a reference
the other passes through the sample
AKA Optical Null Spectrophotmeter
light beam is split with a semicurcual mirrow (beam chopper) |
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Term
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Definition
Diode Array Detector
light becomes diffracted and different diodes read specific absorbency |
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Term
| Advantages of Colorimetry |
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Definition
Visible Spectrophotometry
1st reliable method for drug analysis in blood |
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Term
| disadvantages of colorimetry |
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Definition
few analytes undergo easy chromogenic reactions
poor selectivity/sensitivity |
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Term
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Definition
great application as a detector in HPLC
Can perform directly on sample extracts
use of double beam specs can aid in ID of analyte
can be very useful in understanding enzyme function in immunoassays |
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Term
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Definition
| protien precipitation, back extraction, micro diffusion |
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Term
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Definition
not very selective
higher likelihood of interference |
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