Analysis of Metals in Environmental Samples

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Analysis of Metals in Environmental Samples
M. Paul Field, field_at_marine.rutgers.edu Rm 211a
or 207a Institute of Marine and Coastal
Sciences Rutgers The State University of New
Jersey
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Metals
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Outline

• Trace Metals 1
• Data quality
• Precision
• Accuracy
• Calibration
• Sample preparation

• Trace Metals 2
• FAA
• GFAA
• ICP-OES
• ICP-MS
• Generate real data

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Precision
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Standard deviation
1 Std 68.2 2 Std 95.5 3 Std 99.7
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Error propagation ( -)
Uncertainty Absolute Relative
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Error propagation (x /)
Convert absolute to percent
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Significant figures
Uncertainty defines significant figures
Concentration of Pb In drinking water 0.01
ppm 0.013 ppm 0.0127 ppm 0.01267 ppm
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Quantification

• Semi quant
• External standards
• External standards with Internal standard
• Standard Additions
• Isotope Dilution

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Making Standards
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Making a calibration
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Linear best fit
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Calculating least squares
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Determining slope and Intercept
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Linear best fit
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Std of slope and intercept
Sy is the deviation of several vertical deviations
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Making a calibration
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Calibration uncertainty
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Calibration uncertainty
n number of data points in standard curve k
number of replicates of unknown
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Making a calibration
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Accuracy
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Internal standard
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Certified reference materials
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Certified reference materials
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Students t
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Class project

• The Standard is the tape measure.
• Create a standard curve with measurements using
  any body part.
• Replicate measurements of standards.
• Measure unknowns (several replicates)
• Measure CRM
• Express results with appropriate significant
  figures, precision and accuracy

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Metals of interest
Health Effects The health effects related to
consumption of several metals are presented
below. Keep in mind that research is still being
conducted on the toxicity of most of these
elements. Consult with a physician if your water
contains metals and you suspect health problems
related to metal consumption.   Arsenic is
widespread in the environment due to its natural
occurrence and former extensive use in
pesticides. Symptoms of chronic arsenic poisoning
are weight loss, hair loss, nausea, white lines
across the toenails and fingernails, depression,
and general fatigue.   Cadmium poisoning has
been associated with kidney disease,
hypertension, and possibly genetic mutation.  
Chromium may cause lung tumors when inhaled and
has adverse effects on aquatic life.   Copper
in large doses is dangerous to infants and people
with certain metabolic disorders. On the other
hand, lack of copper intake causes anemia, growth
inhibition, and blood circulation problems.  
Iron in water is not a health hazard by itself
but it may increase the hazard of pathogenic
organisms, since many of these organisms require
iron to grow.   Lead is a cumulative poison,
meaning that it remains in the body following
exposure. Children under age three are most
susceptible to lead poisoning. Minor symptoms
include abdominal pains, decreased appetite,
constipation, fatigue, and decreased physical
fitness. Long-term exposure may cause kidney
damage, anemia, nerve and brain damage, and
death.   Mercury poisoning results in weakness,
loss of appetite, insomnia, indigestion,
diarrhea, gum inflammation, loosening of the
teeth, irritability, memory loss, muscle tremors,
and brain damage following large doses.
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Trace metals

• Acid cleaning
• Filtration
• Acidification
• Dilution
• Internal standard

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Parts per million and billion
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