Metals Flashcards
Arsenic
toxic metal, nonessential element
no known biologic function in humans
arsenic exposure
environmental & toxic
acute poisoning = blood level 600-9300 ug/L
chronic poisoning= blood level 100-500 ug/L
acute arsenic toxicity symptoms
GI nausea, abdomen pain, diarrhea
affects bone marrow, decreases plts, anemia, CV system, renal insufficiency, liver (hepatitis)
chronic arsenic toxicity symptoms
dermatologic & hepatic symptoms
affects CV, CNS, & causes malignant changes
Arsenic methods
prefer urine sample
ICP-MS, AAS, GFAAS
Lead methods
use whole blood & urine
ICP-MS, Zinc protoporphyrin (ZPP) or erythrocyte protoporphyrins, AAS
Mercury methods
blood & urine samples
ICP-MS, cold vapor AAS
Blood & urine ranges for Mercury
blood: 0-60 ug/dL
urine: 0-15 ug/day
toxic urine: >150 ug/L
Lead (Pb) exposure
environmental toxic metal
paint chips & former gasoline additive
lead paint on toys from china
Lead absorption
absorb through lungs & GI tract
inhaled Pb : 30-40% –> binds 94% to hemoglobin & 6% in plasma
Pb half-life is 2-3 weeks in whole blood
Lead excretion
urine: 76%
feces: 16%
hair, nails, sweat etc: 8%
Lead toxicity
children are most susceptible
> 60 ug/dL is toxic
GI & CNS symptoms: pain, colic, constipation, headache, seizures, clumsiness
acute: occupational or asian herbal supplements
chronic: motor weakness, chronic renal insufficiency, anemia, etc
Mercury General
general uses: antibacterial agent, preservative, disinfectant, pesticide, paint, batteries, photographic reagent
no known human need for mercury - toxic metal
used in HgCl as diuretic
vaccine preservative
dental fillings
Mercury metabolism
5-90 days in body depending on type & intake route ( can get in major organs & glands)
can cross blood-brain barrier & placenta (!)
toxicity is due from interaction w/ sulfhydryl group
Mercury toxicity symptoms
headache, tremor, impaired coordination, abdominal cramps, diarrhea, proteinuria, hepatic dysfunciton
Mercury urine screen
called Reinsch test
copper coil in urine w/ HCl, cook for 45 min
metal deposits on coil
mercury on coil looks silvery & shiny
Copper general
needed for biochemistry of # of enzymes & clotting factor V
metalloenzyme to :
ceruloplasmin - major copper enzyme
SOD, cytochrome C oxidase, tyrosinase, metallothionein, dopamin-B-hydroxylase
Copper range
serum: 700-1500 ug/L
urine: 15-60 ug/24 hr
RBC copper: 90-150 ug/L
50-120 mg in body
high concentrations in liver, brain, heart & kidneys
Copper deficiency
malabsorption, malnutrition, chronic diarrhea
signs: osteoporosis, neutropenia, decreased pigmentation, neurologic abnormalities
MENKES kinky hair syndrome
Copper toxicity
Wilson’s disease (!) - neurologic disorder, liver dysfunction, Kayser-Fleischer rings in the cornea
treat toxicity w/ chelation therapy
Iron general
needed for enzymes, hemoglobin, myoglobin, peroxidase, cytochromes etc
Iron range
3-5 grams
2-2.5 g in hemoglobin
Iron Absorption
10% of 1g/day is absorbed through the GI from diet
Iron transport
transferrin
Iron excretion
urine & feces
Iron deficiency
iron deficient anemia - 15% worldwide
Iron Toxicity
iron overload: hemochromatosis seen in diabetes, cirrhosis, hypothyoid, liver cancer
iron as pro-oxidant : lipid peroxidation, atherosclerosis, DNA damage, carcinogenesis, neurodegenerative disease
Iron analysis
Serum iron, TIBC, % saturation, transferrin, ferritin
Manganese general
Mn is essential trace metal: biological functions include-
Mn containing enzymes ( arginase, pyruvate carboxylase, Mn super oxide dismutase)
Mn-activating enzymes (hydrolases, kinases, decarboxylases & transferases)
linked to Fe absorption by the GI (only 2-15% absorbed from small intestine due to effects of iron, cadmium, phophates & fiber)
Manganese Toxicity
symptoms: nausea, vomiting, headache, memory loss, compulsion to cry/laugh
acute: chilean miners madness
chronic: similar to parkinson’s disease w/ akinesia, rigidity, tremors, masklike face
Manganese deficiency
dermatitis, blood clotting defects, hypocholesterolemia
low Mn seen in epilepsy, joint defects, hip abnormalities, heart & bone problems
Manganese methods & ranges
ICP-MS, GFAAS, NAA
serum: 0.43-0.76 ug/L
urine: <2.0 ug/L
blood: 10-11 ug/L
Zinc general
essential metal
biologically important for:
activating enzymes (LD, transferases, hydrolases, isomerases, ligases, & lyases)
activating enzymes in insulin & growth factor
critical for wound healing growth, sexual maturation
maintains cell membrane structure
participates in glycolysis & cholesterol metabolism
important to senses of smell & taste
Zinc distribution in the body
80% in RBC
17% in plasma
Zinc absorption
diet:
need animal protein, unsaturated fatty acids, intake of calcium
decreased absorption: iron, empty stomach, copper, age
Zinc excretion
90% out of feces
Zinc deficiency
symptoms: growth retardation, slow skeletal maturation, testicular atrophy, reduces taste perception
acrodermatitis enteropathica: Zn malabsorption
Zinc toxicity
relatively non-toxic except at high doses
‘zinc fume fever’
Zinc range
blood: 70-120 ug/dL
urine: 140-800 ug/day
RBC have 10x zinc level in plasma
Zinc methods
AAS, ICP-MS, ICP-AES
low serum & low urine zinc tells us patient has zinc deficiency
Other metals of interest
chromium
molybdenum
selenium
Atomic Absorption Spectroscopy (AAS) types
flame atomic absorption spectroscopy (FAAS)
graphite furnance atomic absorption spectroscopy (GFAAS)
cold vapor AAS
ICP-MS
Inductively coupled plasma-Mass spectroscopy
AAS mechanics
radiation: use emitted light from element of interest to get element spectra
atomizer: sample atoms are in vapor so element of interest can absorb light
monochromator: allows specific spectra line to be targeted toward detector
detector: measures the intensity of th elight hitting it
ICP-MS mechanics
increases sensitivity of measuring various metals while decreasing the problems of interferences
uses argon gas to allow free electron movement
looks at ‘mass to charge’ ratio or the molecular mass divided by the ionic charge of the element m/z
Spectroscopy interferences
argon spectral line interference
nearby elements in periodic table have same m/z
doubly charged ions may have same m/z
