Analytical Chemistry Key Terms and Concepts

Vocabulary practice flashcards covering fundamental terms, formulas, instrumentations, and absorption characteristics from analytical chemistry lecture notes.

Carbonyl IR Absorption

A strong infrared absorption characteristic of $C=O$ occurring near $1700\text{ cm}^{-1}$ (specifically $1850\text{--}1650\text{ cm}^{-1}$).

Nitrile and Alkyne IR Absorption

Infrared absorption occurring near $2250\text{ cm}^{-1}$ characteristic of $C\text{≡}N$ and $C\text{≡}C$ triple bonds.

Hydroxyl IR Absorption

A characteristic broad infrared absorption for $O-H$ occurring in the range of $3600\text{--}3200\text{ cm}^{-1}$.

Amine IR Absorption

Infrared absorption characteristic of $N-H$ bonds commonly occurring around $3500\text{--}3200\text{ cm}^{-1}$.

Base Peak

The tallest peak in a mass spectrum.

Semi-Micro Balance Precision

The typical precision of a semi-micro balance, which is $0.001\text{ g}$.

MALDI

Acronym for Matrix-Assisted Laser Desorption/Ionization.

Atomization

The process of converting a sample into free gaseous atoms.

Retention Factor ($k$)

A chromatographic value calculated as distance traveled by solute divided by distance traveled by solvent front, with an ideal range between $2$ and $10$.

Monochromator

A continuous wavelength selector that selects a narrow range of wavelengths in spectrophotometry.

Eluent

The mobile phase in column chromatography.

Eluate

The column effluent collected during chromatography.

Fractional Distillation

A distillation method preferred when the boiling points of components are relatively close.

Simple Distillation

A distillation method most effective when components have a relatively large difference in boiling points.

Proper Sampling Purpose

To obtain a sample that is representative of the bulk material.

Tare Mass

The mass of the empty container.

Elution Power

A chromatographic property primarily determined by the polarity of the solvent.

Volumetric Flask

A glass container calibrated to contain a specified volume, used to prepare solutions to an accurate fixed volume.

Thermal Conductivity Detector (TCD)

A universal detector used in gas chromatography (GC).

Chromatographic Resolution

A parameter that describes the degree of separation between two chromatographic peaks.

HPLC Guard Column

A small column placed before the analytical column to protect the analytical HPLC column.

Boiling Chips

Porous materials added to liquids to promote smooth boiling.

Reversed-Phase Chromatography

Chromatography using a nonpolar stationary phase and a relatively polar mobile phase, where compounds elute from more polar to less polar.

Electron Capture Detector (ECD)

A GC detector especially sensitive to electronegative compounds, commonly used for analyzing Freon-11.

Sand Bath

A heating bath commonly used for temperatures above $250\text{ }^∘\text{C}$.

Aqua Regia Ratio

The standard ratio of $\text{HCl}:\text{HNO}_3$, which is $3:1$.

Hollow Cathode Lamp

A line radiation source used in Atomic Absorption Spectroscopy (AAS) that provides element-specific radiation.

Gradient Elution

The process of changing mobile-phase composition during a chromatographic separation.

Isocratic Elution

Chromatographic separation using a constant mobile-phase composition.

Volumetric Pipet

A pipet designed to deliver exactly one accurate fixed volume.

Measuring Pipet

A pipet used to deliver variable measured volumes.

Photoluminescence

Emission of light following photon absorption.

Retention Time ($t_r$)

The time required between sample injection and detection of a component.

Dead Time ($t_m$)

The time required for an unretained species to pass through the chromatographic column.

Plate Height Equation

The equation $H = \frac{L}{N}$, where $H$ is the height equivalent to a theoretical plate, $L$ is column length, and $N$ is theoretical plate number.

Van Deemter B Term

The term representing longitudinal diffusion in the van Deemter equation.

Spectroscopy

The study of the interaction between matter and electromagnetic radiation.

Selectivity Factor (̑)

Calculated in chromatography as $\frac{k_2}{k_1}$, where $k_2 > k_1$.

Beer's Law

Law stating that absorbance is directly proportional to concentration and path length under dilute, ideal conditions.

Dry Ashing

Thermal breakdown of carbon-containing material that produces mainly $\text{CO}_2$.

Tetramethylsilane (TMS)

The common external standard used in ${}^1\text{H}\text{ NMR}$ spectroscopy.

Coning and Quartering

A sample reduction technique in which the discarded portions are opposite quarters.