ICPMS Trace elements and cannibis Flashcards
What is the proccess of ICP-MS
- Sample introduction
- ICP torch and RF coil
- Interface
- Vacuum
- Universal Cell
- Mass spec
- Detector
What happens in sample introduction
nebulizer and spray chamber - only small droplets enter torch
what happens in the ICP torch and RF coil
argon plasma turns liquid into dried solid, then heated to gas - releasing one electron
What are interferences that can happen in the universal cell
ions generated from the plasma or sample carry the same m:c as the analyte ion
what are ways we fix interferences in the universal cell
chloride correction (math) or collision/reaction cell
what are the 3 modes in the universal cell
Standard, collision, reaction cells
what does a collision cell aka Kinetic Energy Discrimination do
removal based on size using inert gas
cons; background decreases BUT analyte signal decreases too
what does a reaction cell do
removal based on chemical reactions using reactive gas
interferent -exothermic rxn
analyte - endothermic rxn
(better than collision cell bc background decreases and anaylte presernved)
what is the pathway of atomic absorption
light -> chopper -> cuvette/sample -> Detector
another name for the light source in atomic absorption
HOLLOW CATHODE LAMP
- specific for each element being tested
-filled w argon or neon
-quartz glass
what is the principle of the light source
Current applied to cathode will cause ionization = causes sputtering (release metal atoms)
sputtering increases atomic vapor -> collision with inert gas = excitation of atoms = radiant energy and return ground state
what is the principle of sample introduction in atomic
nebulization -> evaporation -> atomization
what is atomization
element attracts e- and produces ground state metal atom
what is emission interference and how to counter it
Light emitted from light source will reach detector - use a chopper bt the lamp and flame
what does the chopper do
pulse beam of incident light to distunguish background and true analyte
what are the two flameless atomic absorption methods
cold vapor and
graphite furnace
both converted into atomic vapor by atomization
princple of cold vapor generation assembly
limited to mercury analysis at RT
uses digestion with acids and sodium borohydride then
quartz window in optical beam
princple of graphite furnace
sample placed on solid support;partition tube
electrical resistance to dry, charr, and atomize
temperatures of graphite furnace stages
dry = 100-120
ashing = 400-800
atomization = 2600
purpose of photomultiplier tubes
detector to measure intensity of signal from monochromator
principle of PMT tubes
crescent shapred dynodes create secondary emission of e- that amplifies signal
main pros and cons of ICP MS
pro = multianalyte analysis with less sample and prep
con = cost
difference of trivalent and hexavalent chromium
3 = essential for human fxn
6 = non essential
where is a source for selenium
soil - animals will have feed w selenium if soil does not contain
what is the cause of wilsons disease and how to solve it
autosomal recessive of copper metabolism issue = accumulation in liver, brain, kidney and eyes
kidney - low serum but high urine copper
cornea - kayser flesicher rings
fixed with zinc therapy
what causes Menkes disease
sex linked recessive of copper absorption decrease
fixed with copper supplements
what are children more susceptible to in lead
neurotoxicity = 50% absorbed - 30% retained
Cannibis name for THC
tetrahydrocannabinol THC
what is the most effect way for THC to enter the body
smoking
how is THC eliminated from the body
70% of dose gone in 3 days (40% feces, 30% uriene)
how long will someone test pos
occasional = days
chronic use = months
what do we analyze for urine, blood, and oral fluid for THC
urine = carboxylic metabolite
blood or oral = THC itself
what is the most effective way for THC to reach max concentration
edibles (delayed effects compared to smoking)
T/F oral fluid is NOT a reliable indicator of blood THC
T - NOT a reliable predictor
what pharmacodynamic effects can weed give
alter time perception, lack concetration and impair memory
why does edibles have lower bioabailability
degredation in stomach = first pass
what is medical marijuana used for
anti-hypertensives (less throw up)
purpose of cannabis act
controlling production, distribution, sale, and possession of weed
protects the youth - under 18
how much cannibis plants can you have in one residence
4
federal vs provincial responsibilityes
federal
- requirements for growers
- standards for farmers
provicial
- license and distribution of weed
what test are done for suspicion of impairment
field sobreity test
walk and turn test
one leg stand
what cross reactivities in THC
pantoprazole
what does the Drug recognition expert perform on suscpicoin on impairment
12 step evaluation
T/F is a lower conc of weed with alcohol a higher offence than low weed itself
T
what is the cut off for oral fluid (after smoking)
2-4 hrs
what is the cut off for whoel blood (after smoking)
residual concentrations exist depending on chronic use so we cannot have a time frame
what vacutainer is used for ICP MS
royal blue top - free from metals
