ISOLATION AND IDENTIFICATION OF POISONS

Question 1

heating a sample to convert the substance into vapor, cooled and condensed back into a liquid state

Answer 1

distillation

Question 2

separation of a crystalloid from a colloid by filtration through a semi-permeable membrane

only applicable if we are trying to separate a crystalloid from a colloid

Answer 2

dialysis

Question 3

based on the miscibility/solubility of the substance in solvents

the substance you are trying to extract has to be miscible or soluble in your solvent for the extraction to occur

miscible: when two liquids with similar polarity are combined and the liquids mix

Answer 3

solvent extraction

Question 4

potent agents present only in very low concentrations

Answer 4

poisons

Question 5

if not properly administered, poisons will not be detected

Answer 5

sample preparations

Question 6

extraction

Answer 6

first step in sample preparations

Question 7

in order to separate target substances from possible interferences which may also be present in the sample

Answer 7

purposes of extracting poisons from drugs or specimen

Question 8

to increase the concentration of the substance comparative to the coextracted matrix (sample or specimen) compounds

Answer 8

purposes of extracting poisons from drugs or specimen

Question 9

if carried out effectively, extraction will increase the chance of an effective analysis.

Answer 9

purposes of extracting poisons from drugs or specimen

Question 10

carried out in cases of poisoning involving heavy metals

precipitating agent, sedimentating agent: milk, raw egg, etc

Answer 10

precipitation and sedimentation

Question 11

usually applied in qualitative detections of drugs of abuse and toxins

Answer 11

chromatography

Question 12

the presence or absence of drugs of abuse and toxins

Answer 12

qualitative detection

Question 13

definite concentration/value of drugs of substance

better than qualitative

Answer 13

quantitative detection

Question 14

part of screening of drugs of abuse/ illicit drugs

central to identifying drugs of abuse

Answer 14

thin-layer chromatography

Question 15

based on relative affinities of substances for polar solid stationary phase and a nonpolar mobile liquid phase

Answer 15

principle of thin-layer chromatography

Question 16

equivalent to the distance travelled by the substance you are trying to separate/ distance travelled by the sol

Answer 16

rf = retention factor

Question 17

best sample for tlc

you can collect a lot of sample in a non-invasive manner

Answer 17

urine

Question 18

usually collected from patients when the mode of introduction of poison is via ingestion

Answer 18

gastric contents

Question 19

samples that are not collected from an individual

Answer 19

non-biological samples

Question 20

sample –> concentration to increase possibility of extracting more –> extraction (basis is whether the substance is acidic (strip1) or basic (strip2) –> separation –> identification

Answer 20

steps in processing sample for tlc

Question 21

mobile liquid phase = solvent = non polar

solid stationary phase = silica gel strip = polar

point a and b = strip1 and strip2

from point a and b, solvent will migrate towards the end portion of silica gel strip

sample A travelled shorter distance = more polar = affinity is in the polar component = more attracted to solid

sample B travelled farther distance = more nonpolar = affinity is in the nonpolar component = more attracted to mobile liquid phase = has more RF

Answer 21

process in thin-layer chromatography

Question 22

the gel strips for the separation are dipped into reagents

there will be unique color reaction

characteristic color reaction and RF = basis for identification

Answer 22

in identification during tlc

Question 23

0.14 rf value

has dark red, purple color reaction

a nonfluorescent substance

Answer 23

morphine

Question 24

required level for detection in tlc

concentration of toxin/poison that should on the strip

Answer 24

1 ug/mL

Question 25

inefficient extraction = insufficient concentration of analyte = negative results

Answer 25

major problem

Question 26

allows quantitative detection of drugs better than tlc used for the analysis of tricyclic antidepressants and their metabolites *absorbance in directly proportional to the concentration of the substance

Answer 26

high-performance liquid chromatography

Question 27

amitriptyline, imipramine, nortriptyline, desipramine, protriptyline they are the most commonly prescribed drugs and they are also used in excess as a drug of abuse in cases of suicide attempts

Answer 27

tricyclic antidepressants

Question 28

gold-standard for the detection and quantitation of volatile drugs and poisons due to high sensitivity and high specificity *ultimate reference method and confirmatory procedure

Answer 28

gas chromatography - mass spectroscopy

Question 29

the method is capable of detecting the substance that is supposed to detect ability to focus on the substance it is supposed to measure can avoid false positives or false negatives

Answer 29

high specificity

Question 30

the method can detect at even low concentrations

Answer 30

high sensitivity

Question 31

the compound/substance are directly heated into gas phase via gas chromatography then, the metabolites will be measured/quantitated via mass spectroscopy

Answer 31

principle of gas chromatography - mass spectroscopy

Question 32

volatilized compound is moved by a gas source into column rings which are encased in an oven. inside the column rings, substances can be separated. once bombarded with electrons, it will be ionized thus carrying a charge. the ionized molecule will be passed on to electric quadrupole field. the quadrupole field serves a a filter. only ions that have narrow range than mass to charge ratios can only pass through then, the data will now be stored in data acquisition computer fragmentogram = results shown in the computer , unique for every substance analyzed in the laboratory, fingerprint pattern

Answer 32

principle of gas chromatography - mass spectroscopy

Question 33

based on the migration of charged solutes or particles in an electrical field utilized for the detection of illicit drugs/highly addictive/illegal substances

Answer 33

electrophoresis

Question 34

charged particles migrates toward the opposite charged electrode * cations = positively charged, attracted to negatively charged or cathode * anions = negatively charged, attracted to positively charged electrode or anode

Answer 34

migration pattern/rule

Question 35

net charge size of particle shape of particle

Answer 35

characteristic that affect the migration of substances

Question 36

driving force = electrical power applied on electrophoresis setup support medium = gel: agarose gel, polyacrylamide gel, starch gel buffer = to maintain the ionized state of particles sample detecting system

Answer 36

5 components of electrophoresis

Question 37

allows the separation and quantification of chemical substance in a wide variety of complex matrices

Answer 37

capillary electrophoresis

Question 38

exceptional separating power rapid analysis high mass sensitivity more economical in terms of reagents required, and only requires minimal sample

Answer 38

advantages of capillary electrophoresis

Question 39

detect gamma-hydroxybutyric acid (GHB): recreational drug known for euphoric effects, rape facilitation drug due to its capacity to reduce inhibitions, doping agent for muscle growth enhancement 3,4-methylenedioxymethampethamine (ECSTASY): recreational drug/club drug toxins and venoms: they are polypeptide complexes, thus cannot be assayed using GC-MS ink analysis: in cases of fraud, estafa, tax evasion gun shot resides and explosives

Answer 39

application of capillary electrophoresis

Question 40

detect the presence of a drug or several drugs of abuse *immunoassays/immunochemical methods, TLC

Answer 40

screening test

Question 41

identify the drug and its concentration *HPLC, GC-MS

Answer 41

confirmatory test

Question 42

process that provides documentation of proper sample identification from the time of collection to the receipt of laboratory results *donor, subject

Answer 42

chain of custody