Miscellaneous Flashcards
Decomposition products that causes false positives of amphetamine immunoassays:
beta-phenethylamine
tyramine
Atropine is an antidotes to which substance?
organophosphates
ionized vs non ionized drugs in terms of polarity and charge
ionized = carries charge, polar; cant pass thru membranes
Main diuretic effect of ethanol is due to:
inhibition of secretion of antidiuretic hormone
Actions of PCP act on what neurotransmitter?
Dopaminergic
Effect observed in 50% of PCP toxicity:
Hypertension
True/False: acidic and neutral drugs produce slightly higher serum concentrations than basic drugs
TRUE
Think about THC (~x2 higher in serum)
How does cyanide produce toxicity?
Inhibit cytochrome oxidase
4 Signs of salicylate poisoning:
Respiratory Alkalosis
Metabolic Acidosis
Hyperpyrexia
Tinnitus
Inducible in chronic ethanol user
MEOS; CYP2E1
Source of 207 and 73 in full scan
Column bleed
How many electrodes does an ion trap have?
3
How is resolution affected if column length doubled?
x1.4
Systematic error affects:
Accuracy
Random error affects:
Precision
Water is a good solvent for:
Salts of organic acids and bases
Instrument best for low polarity compounds such as hydrocarbons
GC/MS
equation elimination rate constant, kel:
kel = clearance/volume of distribution
equation t1/2:
t 1/2 = 0.693/kel
detector that is sensitive for compounds over a wide linear range
FID
detector that is sensitive for trace-level detection of compounds with electronegative functional groups:
ECD
Type of ionization that uses a fine spray of LC effluent that is vaporized in a high temperature tube:
APCI
Type of ionization that used photons as the energy source for the ionization process:
APPI
hapten + immunogenic molecule =
Immunogen
AKA antigen
Hook Effect
antibody./antigen concentration is so high; false negatives
In FPIA: when fluorescein label is free, it rotates freely in solution causing the polarized light emitted to:
increase, decrease, unchange
decrease
think inversely proportional
Immunoassay: drug is found in donors sample–> the unbound enzyme donor reassembles and reacts with the substrate to change the color absorbance:
CEDIA
Produced by animals in vivo; single cell; bind to single epitope on antigen
Monoclonal antibody
2 Disadvantages of orally ingested drugs:
first pass effect
low oral bioavailibility
True/False: Drugs that are weak acids are excreted faster in alkaline urine
True
Drugs that inhibit the activity of ADH:
Cimetidine, Ranitidine
Ethanol BP compared to water:
lower
Used as marker for poppyseed ingestion:
Thebaine
What pH and temperature conditions is Cocaine susceptible to hydrolysis under:
Alkaline and high temperature
Cocaine prevents reuptake of whate 3 NTs?
Dopamine, Serotonin, Norepinephrine
NT associated with Meth
GABA
k1
k2
k3
68%
95%
99%
think of uncertainty (2, 3)
Major metabolic pathway for Arsenic
Urine
Most toxic form of Arsenic
Arsine
Detectors used for CN:
ECD, NPD
Arsenic species from least to most toxic
arsine
A3+
A5+
A0
A0 <A5+ <A3+ < Arsine
DHHS urine cutoff cannabinoids
50 ng/mL
Long term PCP users feel effects after:
15-30 min
plot mean + 1,2, 3 STDEVs
can show difference between normal variation and systematic error
Show of accuracy
Levey-Jennings Chart
Put in order of increasing T 1/2 :
BE, Cocaine, EME
Coc (0.7-1.5), EME (3-8), BE (6-8)
Conway Diffusion: Add sample and sulfuric acid to outer well. Add sodium hydroxide to inner
well and incubate 4 hours. What could be tested for using this procedure?
CN
Order the following according to potency
Fentanyl, Acetyl Fentanyl, Carfentanil, Sufentanil, remifentanil, lofentanil
Acetyl Fentanyl
Fentanyl (approx equal to remi),
Remifentanil,
Sufentanil,
Carfentanil,
lofentanil
In the 1950s PCP use was studied for what application?
Anethesia
Which of the following does the Reinsch test not cover?
Arsenic
Antimony
Lead
Bismuth
Mercury
Lead
Range of THC effects with regard to time
peak?
60%
20%
peak [x] ~ 9 min
60% of peak w/I 15 min
20% w/I 30 min
What is the potency of oral THC compared to smoked?
1/3 - 1/5
What is the name of the structure of synthetic cathinones?
Beta-ketophenethylamine
Less fragmentation with what type of ionization
Chemical Ionization
M+ would predominate
Average pH of blood
7.4
Synthetic Cathinones are the most similar to which drug?
Methamphetamine
What effects would be observed at 0.04 gm% BAC?
Euphoria
Increased sociability
Difficulty with coordination
Coma
Euphoria
Which court case established the confrontation clause allowing defendants to face an expert witness in court?
Melendez-Diaz
Efficiency of a Method is Determined by
accuracy, precision, specificity, sensitivity (limit of detection), linearity, range, robustness, and recovery
[THC] in serum vs blood
x2
A process in analytical chemistry that recovers an organic compound from an aqueous solution. It’s often used in liquid-liquid extraction to improve the compatibility of the extract with measurement and separation techniques.
Back extraction
Example is adding an organic after acidification
Most Prescribed Barb in US
Butalbital
When using a proficiency test to validate a method which of the following are true?
You should use a result averaged from multiple analysts
You should compare to the spiked concentration
You should compare to the average result reported by other labs
None of the above
All of the above
All of the Above
Which of the following is true about confirmation testing?
It is more unique than a screen
It is more specific than a screen
The cutoff is lower than a screen
All of the above
None of the above
All of the above
Why are THC screen (immunoassay?) results often higher than the confirmation?
Cross-Reactivity
What type of agent should you treat glassware with to prevent THC from adhering?
Silyation
What is repeatability a measure of?
Precision
What ratio will be ionized vs unionized for a weak acid at pH 4.0?
1:1
1:2
1:100
1:1000
1:1
half life of 6MAM
Detection window in urine
6-30 min
8 hours
no currently accepted medical use and a high potential for abuse.
Schedule I
EX: heroin, lysergic acid diethylamide (LSD), marijuana (cannabis), 3,4-methylenedioxymethamphetamine (ecstasy), methaqualone, and peyote.
high potential for abuse, with use potentially leading to severe psychological or physical dependence.
Some medical use.
Schedule II
EX: combination products with less than 15 milligrams of hydrocodone per dosage unit (Vicodin), cocaine, methamphetamine, methadone, hydromorphone (Dilaudid), meperidine (Demerol), oxycodone (OxyContin), fentanyl, Dexedrine, Adderall,
moderate to low potential for physical and psychological dependence.
Medical uses.
Schedule III
EX: products containing less than 90 milligrams of codeine per dosage unit (Tylenol with codeine), ketamine, anabolic steroids, testosterone
low potential for abuse and low risk of dependence.
Medical use
Schedule IV
Some examples of Schedule IV drugs are: Xanax, Soma, Darvon, Darvocet, Valium, Ativan, Talwin, Ambien, Tramadol
lower potential for abuse than Schedule IV and consist of preparations containing limited quantities of certain narcotics.; generally used for antidiarrheal, antitussive, and analgesic purposes.
Schedule V
EX: cough preparations with less than 200 milligrams of codeine or per 100 milliliters (Robitussin AC), Lomotil, Motofen, Lyrica, Parepectolin
antagonist
-Used to treat opioid addiction after withdrawal has completed; also used for chronic alcoholics
Naltrexone
antagonist
-Narcan; used to treat opioid ODs (respiratory depression, pinpoint pupils, coma)
Naloxone
Which cannot be with an HPLC?
NPD, UV-VIS, Fluorometer, MS
NPD
Category of naturally derived opiods
Phenanthrenes
ie. Heroin, Morphine, Codeine, Hydromorphone
Category of synthetic opioids
Phenylpiperidines
ie. Fentanyl, Mepiridine
Metabolism of Cocaine
Hydrolyzed to BE (inactive)
Hydrolyzed to EME (inactive)
Demethylated to Norcocaine (active, neurotoxic)
How are compounds retained on a polar column?
Hydrogen bonding/dipole-dipole interaction
Silica phenyl methyl columns
Non-polar
retain non-polar molecules longer
3 types of derivitization
alkylation (add group like ethyl/methyl)
acylation (add acetyl group)
silylation (add trimethyl silyl group)
Cover up active hydrogens with non-polar groups
drugs with -NH, -OH **think THC; bstfa
Type of ionization performed at atmospheric pressure using ions that are produced by a corona discharge
APCI
Workplace testing for urine looks at these three factors:
pH
creatinine
specific gravity
How does diabetes affect BAC?
A diabetic’s blood alcohol content will often be measured quite a bit higher than is accurate because insulin will speed up the metabolism of blood sugar and thus, ethanol, “dumping” more into waste products exhaled by the lungs and into the blood.
lower blood sugar bc liver is processing alcohol not releasing glucose
What is repeatability a measure of?
Precision
Morphine could come from the following sources except:
Hydromorphone
Heroin
Opium
Codeine
6-MAM
Hydromorphone
Hemolysis is a characteristic toxic effect of which of the following:
mercury, arsine, lead, thallium, nickel
Arsine
The following drug is frequently analyzed in plasma specimens by GC – NPD is:
Ethanol, THC, acetone, chlordane, doxepin
Doxepin
The collection of blood in a container with this preservative can falsely elevate GHB concentrations:
Citrate
**not 1% sodium citrate
After an acute dose of cocaine, brain concentrations of this neurotransmitter increase rapidly, and then decrease to below normal concentrations:
Dopamine
This drug acts as a competitive GABA antagonist in humans:
Flumazenil
**antagonist!!!
What type of derivatizing agent is…
Acetic Anhydride
Example of what it’s used for
Acylation
Fent, Opiates
What type of derivatizing agent is…
MTBSTFA
Example of what it’s used for
Silylation
Benzos
What type of derivatizing agent is…
TMPAH
Example of what it’s used for
Alklyating
Barbs
What type of derivatizing agent is…
PFAA
Example of what it’s used for
Acylation
Fluox
What type of derivatizing agent is…
BSTFA
Example of what it’s used for
Silylation
Coke, 6-MAM, Cannabinoids
Time to peak BAC post consumption?
10 min 1-2 drinks
30 min 3-4 drinks
Where is % of EtOH absorbed?
80% small intestine
20% stomach
Levels of EtOH impairment
-0.02-0.12 Euphoria
-0.09 – 0.25 Excitement
-0.15 – 0.30 Confusion/Severe intoxication
-0.25 – 0.40 Stupor
Can only perform retrograde extrapolation if these three requirements are met:
1) Haven’t consumed any etOH since crash
2) Eliminating at constant rate
3) All etOh has been absorbed (usually w/I 0.5 – 1 hr) (decending part of the curve)
Widmark Equation
BAC = [EtOH consumed in grams/(Bodyweight in grams x Vd)] x100
A =ebC
Beer-Lambert Law
A = absorbance
e = molar absorptivity
b = path length
C = concentration
You have an HPLC/UV-VIS injection in which there is background spiking and a flat bottom to the peaks. What could be the cause?
Solvent needs degassing
The sample contains particles clogging something
Examples of Synthetic Cathinones
Mephedrone (4-MMC), M-CAT)
Methylone
Methcathinone
Buphedrone
Bupropion
Pyrovalerone
Alpha-Pyrrolidinovalerophenone (alpha-PVP)
MDPV.
Examples of Synthetic Cannabinoids
JWH-
AM-
RCS-
AM-
-CHMINACA
-FUBINACA
XLR-
-PINACA
results from different labs are linked to a common reference material (RM) and are comparable across analytical methods, testing locations, and time (same results no matter where we send samples)
standardization
This compound is hepatoxic with death occurring after several days.
Acetaminophen
Metabolize to Nordiazepam:
Chlordiazezepoxide
Clorazepate
Diazepam
Parzepam
Halazepam
Diazepam metabolite(s):
Nordiazepam
Temazepam
Nordiazepam metabolite(s):
Oxazepam
Temazepam metabolite(s):
Oxazepam
Henderson-Hasselbalch equation
pH = pKa + log [(ionized)/(unionized)]
pKa strong acid
pKa weak acid
pKa weak base
pKa strong base
Strong acid: < 1
Weak acid: 4-6
Weak base: 7-10ish
Strong base: > 12
ionization method for low to medium polarity molecules that are easily ionized
APCI
pH at which ions are half ionized half unionized
pKa
Primary cannabinoid detected in oral fluid after use
delta-9-THC
What substances concentrate in hair due to ionic bonding to melanin?
Cocaine and Meth
What is present in higher concentrations in hair?
THC or THCCOOH?
THC
THCCOOH would show personal use rather than environmental exposure
Primary compound detected in hair after Cocaine use?
Cocaine parent
Primary compound detected in oral fluid after Cocaine use?
Cocaine parent
Conway Diffusion test using
Sulfuric Acid , NaOH
CN
Which of the following can be elevated in a decomposed sample?
Toluene
N-propanol
Methanol
Hexanol
Pentanol
N-propanol
What benzodiazepines have no active metabolites?
Estazolam, lorazepam, oxazepam