Air Sampling – Key Vocabulary

Vocabulary flashcards reviewing key terms from the Air Sampling lecture, covering sampling methods, blanks, particle behavior, and instrumentation.

Air Sampling

The process of collecting and analyzing air to evaluate health effects, material damage, sources, sinks, emission rates, and to set standards for air-quality management.

Real-Time Analysis

Air-sampling approach in which an instrument measures airborne concentration continuously during sampling, giving immediate data.

Time-Average (Integrative) Analysis

Approach where air is collected over a defined period and later analyzed to obtain a time-weighted average concentration.

Active Sampling

Technique in which a mechanical pump draws air through a sampler, allowing rapid collection (minutes–hours) but potentially altering phase distribution.

Passive Sampling

Technique that relies on a concentration gradient to move pollutants to the sampler; cost-effective, slow (weeks–months), and minimally disturbs phase distribution.

Passive Badge

A compact passive sampler worn or placed in an area to monitor pollutant exposure over time without active pumping.

Breathing Zone

The region within 15–25 cm of a person’s nose and mouth where air is inhaled, critical for health-related sampling.

Field Blank

A blank sample carried to the field to detect contamination introduced during collection, storage, or transport.

Matrix Blank

Field blank that contains the same material as the sample matrix to identify matrix-related contamination.

Reagent Blank

Blank consisting of reagents only, used to check for contamination arising from chemicals added during analysis.

Trip Blank

Sealed blank that travels with samples during transport to detect contaminants introduced in transit.

Analytical Blank

Blank processed through the full analytical procedure to assess contamination from laboratory reagents and instruments.

Laboratory Blank

Blank kept in the lab environment to monitor contamination originating in the laboratory setting.

Tracer (Marker) Compound

A unique, easily quantifiable chemical used to identify and apportion pollutant sources.

Volatile Pollutant

Substance with vapor pressure > 10⁻² kPa that exists predominantly in the gas phase.

Non-Volatile Pollutant (Particulate Matter)

Substance with vapor pressure < 10⁻⁸ kPa that exists primarily as particles.

Semi-Volatile Pollutant

Compound with vapor pressure between 10⁻⁸ and 10⁻² kPa, existing in both gas and particulate phases.

Impaction

Particle-collection mechanism in which larger particles deviate from airflow and strike a surface due to inertia.

Adsorption (on Filters)

Adhesion of gases or very small particles to the surface of a solid sampling medium.

Size Segregation

Separation of particles in a sampler based on aerodynamic size, allowing collection of specific fractions.

Filtration

Sampling principle where air passes through a porous medium, retaining particles on or within the filter.

Aerodynamic Diameter

The diameter of a spherical particle of unit density that settles at the same velocity as the particle of interest, used to predict airborne behavior.

PM2.5

Fine particulate matter with aerodynamic diameter ≤ 2.5 µm that can penetrate deep into the respiratory system.

PM10

Particulate matter with aerodynamic diameter ≤ 10 µm; traditionally monitored for air-quality assessments.

PM1

Ultrafine particulate matter with aerodynamic diameter ≤ 1 µm, now believed to have significant health relevance.

Cyclone (Sampler)

Device that uses centrifugal force to remove larger particles from an airstream, allowing collection of a desired size fraction.

Filter Cassette

Enclosed holder that secures a filter for particulate sampling and protects it during handling.

Support Pad

Porous backing placed beneath a filter in a cassette to provide structural support and prevent filter rupture.

Grit Pot

Component of a cyclone sampler that collects the coarse particles separated from the airstream.