Toxicology Flashcards
(101 cards)
1
Q
How toxic substrates may be determined after adjustment?
A
Method of extraction.
- Water extract: chlorides, urea, nitrates, nitrites, metals
- Extraction with organic solvent: Pesticides, alkaloids, mycotoxines, narcotics
- Steam distillation
- Mineralization: Used metals
2
Q
For what is Gutzeit’s test used?
A
Only for arsenic substances
3
Q
Zn3P2 is determined by?
A
Without adjustment. With AgNO3
4
Q
Which samples can poison determination be done without adjustment of sample?
A
For detection of:
- Arsenic; As
- Mercury;Hg
- Zinc phosphide; Zn3P2
5
Q
What are the steps of intoxification?
A
- Anamnesis
- Clinical symptoms
- Postmortem picture / Pathological -anatomical changes
- CHTA: Chemical toxicological analysis
- Biological experiment
6
Q
How much urine should be used for analysis to get the characteristic colour and odor of each urine?
A
Should withdraw 50ml of urine
7
Q
What is the characteristic colour of urine by presence of Deferoxyamine?
A
Red
8
Q
What is the characteristic colour of urine by presence of Methylene blue?
A
Blue
9
Q
What is the characteristic colour of urine by presence of Sulfonamides?
A
Green/Brown or
Yellow/brown crystals
10
Q
What is the characteristic colour of urine by presence of Ethyleneglycol?
A
Colorless crystals of Calcium oxalate
11
Q
What is the characteristic colour of urine by presence of Nitrosobenzene, phenols, rhubarb?
A
Brown or black
Phenols can also be blue or green
12
Q
What is the characteristic colour of urine by presence of Quinine?
A
Wine red or brown
13
Q
Odor of garlic in urine due to?
A
Arsenic or Phosphorous(oxalic acid)
14
Q
Odor of bitter almond in urine due to?
A
Cyanide
15
Q
CHTA consist of 3 steps
A
Extraction
Purification
Detection
16
Q
What is the procedure in sampling of fish?
Intoxificated fish
A
- send the whole fish
- Send water from intoxicated area (1l)
- Add map of intoxicated area
- Send samples from place above the possible source of intoxication
Should be no bubbles in GLASS bottle to not change the oxygen levels!!!
17
Q
In fish poisoning we withdraw fish and water from CHTA. The water is withdrawn in amount?
A
At least 1l in a GLASS bottle. Completely filled bottle.
18
Q
What is the procedure in sampling of bees?
A
- Should be a sample of about 600 gram of dead bees.
- Sample of treated plants of 200g sent to laboratory
Sent within 72h after treatment
19
Q
Purification method of a sample of CHTA can be done by?
A
Column chromatography
20
Q
Which methods are used for detection of toxic substances?
A
- Spectrophotometry (UV-light, IR light, Visible light)
- Physical method
- Polarography (Not used anymore)
- Chromatographic methods
- Thermo emissing method
21
Q
What is zinc phosphide?
A
A rodenticide
22
Q
Ingestion of mercurial fungicial preparations or overdosage of some antidotes are frequent for?
A
Agronal or Arseinc in selenium poisoning
23
Q
What happens when Zn3P2 enters body?
A
- When in contact with HCl in stomach it will transform into PH3.
- Smell of stomach content when open is «garlic»
Zn3P2 + 6HCl -> PH3 + 3ZnCl2
PH3 = Phosphine and is HIGHLY TOXIC. Not used in EU anymore
24
Q
Clinical signs of Zinc phosphide toxification?
A
( Zn3P2 )
- Smells like garlic
- Bradycardia
- Spasms
- Haemorrhage to digestive organs
25
A positive result in Zn3P2 determination is if?
The filter paper soaked in AgNO3 turns black. The rest stays yellow
Due to reduction of metallic silver by the released PH3 gas
26
Zinc phosphide is determined by?
Without adjustment
27
What belongs to the group of spasm poision?
Arsenic
28
Which are the detection methods?
- Specrophotometry
- Mass spectrophotometry
- Physical method
- Chromatography
- Atomic absorbin spectrophotometry(AAS)
- Polarography (electro-chemical method)
- Thermo emissing method
29
Can CHTA samples be preserved by chemicals before testing?
No
30
Which organ is the best to take a sample from?
STOMACH - It's content. ( From alive animal)
Otherwise LIVER.
31
In case of a positive case with arsenic determination which color changes can be observed?
Yellow and black crystals of AgNO3.
Crystals of AgNO3 turns yellow and later it turns black.
32
Arsenic is determined in biological sample?
Without adjustment - Gutzeit's test
33
Typical for Mercury ?
Evaporates rapidly + vapors inhaled in lungs -> blood brain barrier and accumulates in kidneys.
- Kill the erythrocytes
- Black gingiva (tannhold)
34
Compounds needing water extraction for determination are?
What is being determined?
Nitrate, Nitrite and NaCl.
Acidifying it with HNO3-.
Determining unmetabolized metals.
35
Toxically important metal elements are.......... that can be determined by two analytical methods, which?
....... = cations
Determined by qualitatively and quantitatively methods.
36
Reaction with ammonia hydroxide in presence of copper will show which colour creating?
In presence of Cu2+ the color will be violet.
Lead, Pb2+ = Black
Zinc, Zn+ = Yellow
37
Pb is qualitative determined with ?
H2SO4 (white ppt)
38
Hg2+, Mercury is qualitative determined with ?
Potassium Iodide; KJ
39
How can treatment of heavy metal poisoning be done?
By EDTA
40
Write down the ethology of poisoning:
Poison is every chemical substance qualitatively or quantitatively, different from the organism and its harmful from the chemical or physical aspects.
41
Determination methods pre/post adjustment?
Mineralization, water extraction, stem distillation, organic solvent extraction.
42
Samples for CHTA can be preserved by?
Freezing or by use of formaldehyde
- Cooling without the use of chemicals (freezing) or by use of formaldehyde(1:9 of neutral formaldehyde – 1 part of 40%formaldehyde, 9 parts of water)
43
Can samples of CHTA be preserved with chemicals?
No chemicals!
Only by cooling/freezing
44
The normal value of Methemoglobin, MtHb in organism?
In a low concentration in RBC
| 3 +/- 2%
45
What system detoxes MtHb to Hb in organism?
The MtHb reduction system by MtHb reductase enzyme
Excess circulating MtHb is efficiently re-converted into reduced haemoglobin
46
How do we quantitative determine MtHb in blood?
By Spectrophotometry
47
What causes degradation of methemoglobin ?
Effects of Nitrites, NO2
48
Color of blood with higher concentrations of MtHb is?
Dark brown / chocolate brown
49
Color of blood with Cyanomethemoglobin, MtHbCN is?
Bright red
50
Color of blood with Sulphaemoglobin, HbSH is?
Grey or Black
51
Color of blood for carboxyhemoglobinemia is?
Bright red
52
How is methaemoglobinaemia clinically manifested?
By cyanosis
53
Methaemoglobin present in blood is due to?
Metabolism
54
Therapy for MtHb poisoning (high nitrites)
By Methylene blue I.V. 1mg / 1kg body weight in a 1 -2 % saline solution.
- Reduced Fe3+ to Fe2+
- By transfusion or O2 mask also.
55
What is Methemoglobinemia?
A condition where a part of the normal blood pigment hemoglobin is present as methemoglobin.
56
Mention a methemoglobinemic agent
Nitrites
57
What is the function of nitrites in hemoglobin
Penetrate into erythrocytes and oxidize Fe2+ --> Fe3+ of the hemoglobin.
Fe3+
- Not able to bind oxygen and transfer oxygen to tissues
58
Nitrates is reduced by rumen and intestine into?
Nitrites
- Causes methemogobinaemia
59
Anticoagulant rodenticides inhibit...?
The production of pro-thrombin
60
Polarography is...?
An electrochemical / quantitatively method
61
What is AAS?
A reference method for determining toxic compound
- A quantitatively method for cation determination
62
Which essential heavy metal is important for insulin production?
Chromium, Cr3+
63
What is Itai Itai disease?
Bones breaking by slightes movement, even breathing.
- Carmium enters body instead of Calcium.
- Bones and kidney primarily affected
64
Which metal has high affinity of the central nervous system?
Mercury
65
What is an antidote to Selenium?
Arsenium
66
Sulphemoglobin is formed after exposure to?
Hydrogen sulfide or carbon disulfide
67
Carboxyhaemoglobin is formed after exposure to
....
68
What system detoxicate MtHb to Hb in the organism?
MtHb normally in low concentration in RBC, if higher it must be reconverted to reduced Hb by intraerythrocytary MtHb reductase.
69
What is the normal urea concentration?
2-7mmol/l ( >12mmol/l=toxic)
70
Mechanism of creating MtHb
| chemical formula
NO3--> NO2- : Fe2+ --> Fe3+
| Iron is oxidized.
71
Compounds that cause MtHb-emia?
- Nitrites if pH is higher: NH2 passes rumen wall, pH lower: NH4+ cannot pass.
- Chlorates
- Chromium
- Carbamates
- Oxides of nitrogen
- Aromatic nitro and amino compounds
72
What is LD50?
Lethal dose for 50% of the exposed population under controlled conditions.
73
LD50 of urea in unaccostumed ruminants are?
0,3-0,5g /kg
74
What is the therapy for urea poisoning?
* 0,3-0,5 % Acetic acid or vinegar do decrease pH from 8-9 down to 6-6.8
- 3-5 litres for cattle
- 1L for sheep.
* Cold water to decrease metabolic activity in rumen
* Also imp to increase amino acid content.
NH3 + HCl --> NH4+ + Cl-
75
Therapy of cyanide poisioning?
- Sodium nitrite; is applied and MtHb is formed, cyanide binds to it and form MtHbCN.
- Sodium thiosulfate; is the applied and SCN- (non-toxic) is formed and eliminated by urine.
76
35. Which are the chemicals which need water extraction as part of their determination?
Nitrate and Nitrite
77
Therapy of Zn3P2 poisioning?
- tube to release phosphine gas from stomach
- remove stomach and intestine content (tube or laxative)
- spasms treated by antispasm.
78
2. Write down the therapy in methemoglobinemia poisoning
Methylene blue
79
How much indicates that there is a urea toxification ib blood?
Higher levels than 12mol/l
80
What is a typical "First aid" in toxification?
Diazepam
81
Course of urea poisoning
- Increase of pH in rumen content
- Tremor
- Increased respiratory rate
- Pulmonary edemea
- Foamy salivation
- Grinding teeth
- Cyanosis
- Hemorrhage of intestine and BV
- Hyperthermia
- Death within 2 hours.
82
What is the normal value of Urea concentration in milk?
- 2-7 mmol/L
- NB! 8-12 - dubious
- >12 - intoxication
83
Urea conc. In blood is determined by?
Water extraction and spectrophotometry
84
Write down the ethiology of poisoning caused by absorbable noxa?
- per os with food.
- per os with water
- per inhalation
- per cutis
85
What kind of chromatographic methods do you know?
- TLC – thin layer chromatography
- GC – gas chromatography
- HPLC – high pressure liquid chromatography
86
NaCl is excreted by/NaCl is determined from?
Water extraction
87
How can chlorides be determined
By spectrophotometry
88
Most common chloride?
NaCl as a salt. Is a physiological solution
89
Explain chlorine toxification
Most common in pigs.
- Causes weakening / paralysis of hindlimbs in piglets and to sit like dog "sitting dog" position
- Lead to tremor, spasms, incoordinated moving, death and lead to death within a few days if not treated.
- Typical is strong perfused diarrhea
Have to check superficial reflexes which during toxification doesn't show any response.
Can cause BRAIN EDEMA
90
What causes NaCl toxification?
Too high intake of NaCl with food and too little water.
NaCl is a feed additive (mineral supply) but if too high doses toxic.
In pigs common with 0,5 - 1% of NaCl
91
Lethal dose of NaCl for pig?
50 - 200g or 2.2g/kg BW
OR
3-4% of NaCl in diet for cattle, pig and poultry
92
Therapy of NaCl toxification
Administration of fresh water in small amounts and Calcium.
Too much water too quick can trigger nerve signs due to brain edema.
High mortality right. Over 50% even if therapy
In small animals can give
- Solution of dextrose
- Isonic solution of salt
93
Endosulfan is a ..... ?
Pesticide
94
What are 4 distillation methods?
- Water extraction
- Mineralization
- Organic solvent
- Steam distillation
95
Toxification of Nitrate
Nitrate is very reactive and is easy transferred into Nitrite.
- Horses sensitive!
- Ru less sensitive.
"Salt hungry animals" may consume nitrate fertilizers and cause poisoning.
Blue baby syndrome = Babies are sensitive to nitrates in water
Nitrates are reduced by rumen and intestinal organs into Nitrites --> Nitrogen I oxide --> Ammonia hydroxide --> Ammonia
(Absorbed into blood stream and combined with hemoglobin --> Methemoglobin)
NO3- --> NO2- --> N2O --> NH2OH --> NH3
96
How can Nitrite toxification be treated?
1st by enough water
| 2nd Adrenaline in horses
97
Which colour indicator is specific for qualitative determination of NO2-?
Griess-Illosway indicator
"Reagent paper containing stabilized Griess agent"
98
How can Nitrate / Nitrite be determined?
By spectrophotmeter
99
If there is nitrates present in water extract what will the obtained color be?
Will form a blue ring on the surface
| Will be reduced to nitrites
100
Reference value of nitrites in drinking water ?
0,5mg/l
101
Reference value of nitrates in drinking water?
50mg/l
| For infants up to 15mg/l
