Systematic qualitative organic microanalysis: Determination of the refractive index of liquids

Review of Organic Microchemistry

“…Capillary tubes are best filled by inserting the end of the capillary in the liquid contained in a small vial which is placed in a filter flask (Figure 17) and evacuated momentarily (6). This is a great improvement over the usual method of heating and cooling the capillaries.…”

“…6. The development of color on the addition of a suitable reagent and determination of the quantity of impurity by means of…”

Systematic Qualitative Organic Microanalysis

“…Determination of Specific Gravity HERBERT K. ALBER Microchemical Laboratory, Biochemical Research Foundation of the Franklin Institute, Philadelphia, Penna. IN THE identification of an unknown organic liquid, the specific gravity is one of the most important physical constants. Most available methods for the determination of specific gravity are designed for special purposes and do not meet the requirements which have been proposed for the systematic scheme of qualitative organic microanalysis (2,8,6,9). An accuracy of from 0.1 to 1 per cent is considered satisfactory for the purpose of identification.…”

“…The schlieren method (4,8,18) allows the determination of the refractive index (6) as well as the specific gravity on a few cubic millimeters of the liquid sample: For specific gravity the sensitivity is about 0.0001, and the accuracy is about 0.0005. In colorless liquids the difference between the refractive indices of liquid to be tested (fluid sample) and reference liquid (static sample) makes the direction of flow discernible; in the case of identical specific gravities a cloud effect around the end of the capillary is observed, especially if the tip of the capillary pipet containing the unknown fluid sample is bent at a 90°a ngle.…”

A new microtechnique for the analysis of liquids by displacement adsorption

“…1. The fundamental work was done by B. Mair a in 1945 who showed, that a sharp separation of aromatic and 7 aliphatie hydrocarbons was possible.…”