Nitrate test to 2.5 micrograms and a concentration of 1 in 25,000 parts. Devarda's alloy (Copper/Aluminium/Zinc) is a reducing agent. When reacted with nitrate in sodium hydroxide solution, ammonia is liberated. The ammonia formed may be detected by its characteristic odor, and by damp red litmus paper's turning blue, signalling that it is an alkali — very few gases other than ammonia evolved from wet chemistry are alkaline. Aluminium is the reducing agent in this reaction that will occur. Diphenylamine may be used as a wet chemical test for the presence of the nitrate ion. In this test, a solution of diphenylamine
Squib (sketched concept or visual solution) verb ("let me squib something to show you what I mean"). First heard use: Alberta College of Art and Design, Calgary, Alberta, Canada. Circa 1987 Squib (sketched concept or visual solution) The term squib is sometimes used to describe a quick drawing of a visual composition or a proposed graphic solution. A rough sketch to demonstrate an idea. The origin of the term, "squib" as it relates to a sketched concept or idea is currently unknown, but has been adopted as industry slang by creative directors, art directors and designers in the creative advertising and marketing communications industries in Western