Aqueous solutionAn aqueous solution is a solution in which the solvent is water. It is mostly shown in chemical equations by appending (aq) to the relevant chemical formula. For example, a solution of table salt, or sodium chloride (NaCl), in water would be represented as . The word aqueous (which comes from aqua) means pertaining to, related to, similar to, or dissolved in, water. As water is an excellent solvent and is also naturally abundant, it is a ubiquitous solvent in chemistry.
Buffer solutionA buffer solution (more precisely, pH buffer or hydrogen ion buffer) is an acid or a base aqueous solution consisting of a mixture of a weak acid and its conjugate base, or vice versa. Its pH changes very little when a small amount of strong acid or base is added to it. Buffer solutions are used as a means of keeping pH at a nearly constant value in a wide variety of chemical applications. In nature, there are many living systems that use buffering for pH regulation.
Phthalic acidPhthalic acid is an aromatic dicarboxylic acid, with formula C6H4(CO2H)2. Although phthalic acid is of modest commercial importance, the closely related derivative phthalic anhydride is a commodity chemical produced on a large scale. Phthalic acid is one of three isomers of benzenedicarboxylic acid, the others being isophthalic acid and terephthalic acid. Phthalic acid is produced by the catalytic oxidation of naphthalene or ortho-xylene directly to phthalic anhydride and a subsequent hydrolysis of the anhydride.
2007 pet food recallsBeginning in March 2007, there was a widespread recall of many brands of cat and dog foods due to contamination with melamine and cyanuric acid. The recalls in North America, Europe, and South Africa came in response to reports of kidney failure in pets. Initially, the recalls were associated with the consumption of mostly wet pet foods made with wheat gluten from a single Chinese company. After more than three weeks of complaints from consumers, the recall began voluntarily with the Canadian company Menu Foods on 16 March 2007, when a company test showed sickness and death in some of the test animals.
