Analytical Chemistry & Spectroscopy — 9 Terms Defined

Sampling Analytical Chemistry & Spectroscopy g The process of selecting a small portion of material that genuinely represents the bulk being analysed.

Secondary Standard Analytical Chemistry & Spectroscopy mol/L A solution whose concentration has been established by titration against a primary standard.

Sensitivity Analytical Chemistry & Spectroscopy Various The change in an instrument's response for a given change in analyte concentration. S = dSignal / dConcentration

Specificity Analytical Chemistry & Spectroscopy Dimensionless The ability of a method to measure the analyte accurately in the presence of everything else in the sample.

Spin–Spin Coupling Analytical Chemistry & Spectroscopy Hz The splitting of an NMR signal into multiple lines caused by interaction with neighbouring non-equivalent nuclei. n + 1 rule

Standard Deviation Analytical Chemistry & Spectroscopy Various A statistical measure of the spread of a set of repeated measurements about their mean. s = √(Σ(xᵢ − x̄)² / (n − 1))

Standardisation Analytical Chemistry & Spectroscopy mol/L The determination of the exact concentration of a solution by titrating it against a primary standard. M₁V₁ / n₁ = M₂V₂ / n₂

Stationary Phase Analytical Chemistry & Spectroscopy Dimensionless The fixed material in a chromatographic system with which the sample components interact as they pass.

Systematic Error Analytical Chemistry & Spectroscopy Various An error that shifts every result in the same direction by a similar amount.