Components:

(1) Anthracene, C₁₄H₁₀; [120-12-7] NIST WebBook
(2) Sodium chloride, NaCl; [7647-14-5] NIST WebBook
(3) Water, H₂O; [7732-18-5] NIST WebBook

Original Measurements

Schwarz, F. P.; J. Chem. Eng. Data. 1977, 22, 273-7.

Variables:

Ambient temperature: 8.2 - 30.2 °C
Salinity: 30 g(2)/kg sln

Prepared by:

D. Mackay, W.Y. Shiu

Method/Apparatus/Procedure:

The solubility of anthracene in NaCl solution was determined by fluorescence and UV absorption measurements. In the fluorescence method, saturated solution was prepared by adding excess amount of anthracene to an air-tight 1x1 cm quartz fluorescence cell containing 5 mL salt solution. The cell was rotated at 20 rpm for at least 72 hr in a thermostated water bath and then its fluorescent intensity was measured at 258 nm. The spectrofluorimeter employed a ratio-photon counting mode where anthracene concentration was linearly related to the fluorescence signal. The UV method was used to obtain the absorptivity of anthracene in ethanol therefore provide an absolute solubility scale for the fluorescence method.

Source and Purity of Materials:

1. Anthracene: purity >99 mole%
2. Sodium chloride: reagent grade
3. Water: distilled over a KMnO₄ - NaOH solution and passed through a Sephadex column.

Estimated Errors:

Ambient temperature: ±0.1°C (author)
Mass concentration (m/v) (1): ±4.3% (author)