Introduction & Analytical Techniques in Toxicology

Flashcards covering definitions, analytical methods, and clinical markers in toxicology based on the Rose Daher lecture.

Toxicology

A broad multidisciplinary science whose goal is to determine the effect of chemical agents on living systems.

Clinical Toxicology

The analysis of a chemical or drug in body fluids for the purpose of patient care.

Forensic Toxicology

The study that addresses legal issues of the effects of toxic substances on either living persons or as a cause of death.

Environmental Toxicology

The study of the harmful effects of exposure to environmental agents from natural or industrial sources.

Toxidromes

Specific symptom complexes associated with certain toxins, such as the narcotic toxidrome characterized by miosis, bradycardia, and shallow respirations.

Antidote

Any drug that increases the median lethal dose ($LD_{50}$) of a toxin.

N-Acetylcysteine (NAC)

An antioxidant antidote for acetaminophen toxicity that is metabolized to cysteine, which is used to synthesize glutathione ($GSH$).

Anion Gap

A calculated gap used to identify certain toxins, determined by the formula: $Na^+ - [Cl^- + HCO_3^-]$.

Osmole

The amount of a substance that yields, in ideal solution, the number of particles that would depress the freezing point of the solvent by $1.86\,K$.

Osmolality

The number of osmoles of solute per kilogram ($kg$) of solvent, measured in labels using osmometers via colligative properties.

Osmolarity

The number of osmoles of solute per litre ($L$) of solution, often calculated using the formula: $(1.86 \times [Na^+]) + [glucose] + [urea] + 9$.

Osmolar Gap

The difference between measured osmolality and calculated osmolarity ($\text{Osmolality} - \text{Osmolarity}$).

GC/FID

Gas Chromatography with Flame Ionization Detection; used for clinical detection and quantitation of methanol, ethanol, isopropanol, and acetone.

Triage Tox Drug Screen

A competitive fluorescence immunoassay for the qualitative determination of parent compounds and major metabolites of drugs of abuse in urine.

Thin Layer Chromatography (TLC)

A screening technique where support particles are spread on a flat plate and the mobile phase travels up the plate through capillary action.

Anodic Stripping Voltammetry (ASV)

An electrochemical technique for determining ionic metals where the analyte is electrodeposited on a working electrode and then oxidized during the stripping step.

Graphite Furnace Atomic Absorption Spectroscopy (GFAAS)

The reference method for blood lead analysis where ground-state atoms in a furnace absorb specific spectral lines emitted by a hollow cathode lamp.

Inductively Coupled Plasma Mass Spectroscopy (ICP-MS)

An analytical technique that uses high-temperature plasma to ionize a sample before it is sampled into a mass spectrometer to determine isotope ratios.

Naloxone

The specific antidote used for treating narcotic overdoses involving opiates.

Specimen Validity Test

A semi-qualitative color comparison screen using reagent pads to check urine for creatinine, nitrite, glutaraldehyde, pH, specific gravity, and oxidants.

BLL Reference Range

The current blood lead level reference range, which was lowered to $3.5\,\mu g/dL$ in October 2021.