Phenol is an organic compound that is similar to alcohol but has very strong hydrogen bonds. Phenol occurs as a colorless liquid or a white solid when subjected to room temperature. It is considered to have high boiling points, is highly toxic, and also caustic. The compound is used as an intermediate in industrial synthesis and utilized in various household products. Phenol is hazardous as the material is toxic and can rapidly penetrate the skin resulting in serve burns. It advisable for people to wear protective gears such as gloves when handling substances with high phenolic compounds and use leather shoes in areas where spills are present.
Identification of Phenol
Phenols have natural sources such as fruits but also occur in environmental pollution such as spills. The presence of phenols in liquids is identified through the application of the ferric chloride test. The test is carried out by adding aqueous ferric chloride to the substance being tested (Paiva-Martins, & Gordon, 2005). The presence of phenol acid is observed when the reaction forms a violet, blue, green, red-brown, or a purple color. It is recommended to wear gloves to avoid corrosion from the phenol compounds. Phenolic compounds in the environment can be tested through the Liebermann’s reaction. The test substance is mixed with a crystal of sodium nitrite, forming a mixture that is dissolved in concentrated sulphuric acid. The mixture is heated to form a green to a blue solution that is diluted with water to form a yellow or brown, red, or violet solution, respectively. This illustrates the presence of phenolic compounds in the test substance.
Nitric Acid (>70%)
Nitric Acid is a colorless liquid that contains nitrogen oxoacid, where the nitrogen atoms are strongly bonded to the hydroxy group and have equivalent bonds to two oxygen atoms that remain. Nitric acid is considered a reagent, protic solvent, and a strong oxidizing agent. Nitric acid is a good conductor of electricity as it ionizes readily in various solutions. The compound is used for industrial purposes in manufacturing fertilizers, explosives, dye intermediates, and organic chemicals. Nitric acid is very toxic when inhaled, corrosive to tissues or metals, and has adverse health effects.
Identification of Nitric (>70%)
Nitric acid (>70%) is present in the ambient air and can be identified through the gas chromatography or the photoionization detection process. The process entails the monitoring of nitric acid concentration in the air where nitric acid is separated and preconcentrated from specific nitrate. The ambient air is sampled in a diffusion tube known as the denuder, which is coated with aluminum sulfate (Tsikas, Schwarz, & Stichtenoth, 2010). Nitric acid collected in the denuder is released through the thermal desorption process and is analyzed selectively through gas chromatography. The identification process highly concentrates on the discrimination present between the gaseous Nitric acid and any other particulate nitrate. Through the gas chromatography denuder without in-line filters are used for air to pass under laminar flow conditions (Phillips et al., 2013). The conditions contribute to great differences in the diffusion rates of the gas molecules and the particles which contribute to the gas-particle separation. Also, the nitric acid (>70%) collected in a denuder, which is coated with sodium carbonate, can be analyzed through ion chromatography to analyses for nitrate content.
The classical brown ring test is a test that can be applied in the identification of Nitric acid. The test entails dissolving the sample substance in an iron (II) sulphate solution. A solution of concentrated Sulphuric acid dispensed in small volumes to the mixture, which forms a separate layer. A junction is observed between the two layers, which is in the form of a brown ring indicating positive results for the presence of nitric acid.
Paiva-Martins, F., & Gordon, M. H. (2005). Interactions of ferric ions with olive oil phenolic compounds. Journal of agricultural and food chemistry, 53(7), 2704-2709.
Phillips, G. J., Makkonen, U., Schuster, G., Sobanski, N., Hakola, H., & Crowley, J. N. (2013). The detection of nocturnal N2O5 as HNO3 by alkali-and aqueous-denuder techniques. Atmospheric Measurement Techniques, 6(2), 231.
Tsikas, D., Schwarz, A., & Stichtenoth, D. O. (2010). Simultaneous measurement of [15N] nitrate and [15N] nitrite enrichment and concentration in urine by gas chromatography mass spectrometry as pentafluorobenzyl derivatives. Analytical chemistry, 82(6), 2585-2587.