Trace Elements and Instrumentation Techniques

Essential Trace Elements

• Essential trace elements often participate in enzymes and metalloproteins.
• Dietary requirements are the smallest nutrient amounts for optimal function.
• Nonessential elements are not needed for bodily function but can be toxic.

Instrumentation and Methods

• Atomic Absorption Spectrometer (AAS): Used for trace/toxic metal analysis.
  • Can use flame (FAAS) or flameless atomization (GFAAS).
• Emission spectrum consists of lines at different wavelengths, associated with specific transitions.
• Inductively Coupled Plasma Mass Spectrometry (ICP-MS): More sensitive than AAS, with a wide range of analyzable elements, and fewer interferences.
• Atomic Emission Spectroscopy: Analyzes element emission after aerosol conversion.
• Atomic Absorption Spectroscopy: A process for element quantification through optical radiation absorption by gas-phase atoms. Follows the Beer-Lambert Law. Employs a radiation source, atomizer, monochromator, and detector.

Sample Collection and Processing

• Use special collection tubes (royal blue, often with EDTA).
• Avoid inserting pipettes; use pouring transfers.
• Do not use wooden applicators on serum samples.
• If submitting hair/nails, use separate containers to avoid contamination.

Atomic Emission Spectroscopy

• Consists of:
  • Source (sample atomization for excited-state species formation).
  • Wavelength-selecting device (monochromator, for radiation dispersion and spectral line isolation).
  • Detector (for radiation intensity measurement).

Atomic Absorption Spectroscopy

• An analytical technique quantifying elements through optical radiation absorption by gas-phase atoms.
• Key components:
  • Radiation source (emits analyte element spectrum).
  • Atomizer (creates atoms of interest). Common atomizers in flameless AAS are graphite tubes.
  • Monochromator (separates radiation and analytical line).
  • Detector (measures radiation intensity).

Inductively Coupled Plasma Mass Spectrometry (ICP-MS)

• Plasma in ICP is ionized gas (typically argon) with free electrons.
• Components:
  • Ion source
  • Mass analyzer
  • Ion detector

Aluminum (Al)

• Silver-white, crystalline, and ductile metal.
• Most abundant metal in Earth's crust.
• Often combined with other elements (oxygen, silicon, fluorine).
• Toxicity signs may include encephalopathy, proximal myopathy, increased infection risk, anemia, and bone disease.

Arsenic (As)

• Ubiquitous element with both metallic and nonmetallic properties.
• Main exposure source is food.
• Acute exposure may affect GI, BM, CNS, renal, hepatic systems.
• Chronic exposure associated with dermatologic, cardiovascular, CNS, hepatic, and malignancy issues.
• Blackfoot disease is a severe peripheral vascular disease linked to arsenic exposure.
• Arsenic trioxide is a lethal poison; antidotes include dimercaprol, penicillamine, and succimer.

Cadmium (Cd)

• Soft, bluish-white metal, easily cut.
• Not biologically essential.
• Exposure routes include inhalation and ingestion.
• Cigarette smoking increases cadmium levels.
• Exposure can affect liver, bone, immune, blood, and nervous systems. EDTA is used as a chelating agent in poisoning.

Chromium (Cr)

• Makes rubies red and emeralds green.
• Abundant element, part of stainless steel manufacture.
• Cr6+ is more readily absorbed and toxic than Cr3+.
• Cr3+ is a dietary essential; Cr6+ is a powerful oxidizer and can be toxic/carcinogenic, causing respiratory and skin issues.

Copper (Cu)

• Soft, tough metal with good electrical/heat conductivity.
• Forms alloys (brass, bronze, cupronickel).
• Primarily excreted through the bile; urine/sweat excretion is minimal.
• Deficiency linked to premature infants, malnutrition, and diseases.
• Key signs of deficiency include neutropenia, hypochromic anemia, osteoporosis, and neurologic issues.
• Extreme copper deficiency (Menkes disease) causes hair and developmental problems.
• Wilson's disease is related to copper accumulation.
• Serum ceruloplasmin levels and direct copper measurements are crucial for diagnosis.

This quiz covers essential trace elements and their roles in the body, as well as various instrumentation methods used for their analysis. Focus topics include Atomic Absorption Spectrometry and Inductively Coupled Plasma Mass Spectrometry. Test your knowledge on both nutritional requirements and analytical techniques.