List of detection reactions

Ring test, a classic nitrate test

Detection reactions are chemical reactions that are as specific as possible, which qualitatively indicate the presence of an ion or a group of substances and which can be carried out with simple means. Some of these reactions can also be used for quantitative determinations. The products of the reaction are usually colored in a characteristic way and are mostly caused by precipitation , complex formation or redox reaction . But digestion processes and flame coloration are also counted among these reactions.

Nowadays they play a subordinate role in analytical chemistry , but are used in the training to become a chemist for didactic reasons, in order to impart precise analytical work and knowledge of chemical chemistry as well as to practice handling laboratory equipment.

Inorganic

Anions

connection	Evidence as / by means of	Reagents	indication	Disorder	Experiment instructions
Borates	Trimethyl borate	Methanol	green flame		Evidence as methyl ester
Borates	Rosocyanine	Curcumin	red-colored solution
Carbonates	Carbonate	HCl , barite water	Cloudiness		Evidence as barium carbonate
Carbonates	carbon dioxide	HCl	Gas evolution	Sulphides, common metals
Cyanide	Berlin blue	Iron salts	deep blue solution		Proof as Berlin blue
Cyanide	Iron (III) thiocyanate	Ammonium polysulphide , ferric chloride	deep red solution		Detection with polysulfides
Cyanide	Lassaigne trial	Iron (II) sulfate	deep blue solution, with alkali ions precipitate
Chlorides , bromides , iodides	Halide detection with silver nitrate and ammonia	Silver nitrate , ammonia water	white precipitate	Copper cations	Halide detection with silver salt solution
Bromides	Bromide detection	sulfuric acid	brown fumes		Detection of bromide with sulfuric acid
Bromides , iodides	Evidence as elemental bromine and iodine	Chlorinated water or chloramine T with hydrochloric acid	Bromine: orange-brown iodine: pink-violet	Sulfide , thiosulfate	Evidence as bromine and iodine
Fluoride	Fluoride # detection	Sulfuric acid , silica	Etched glass, silicate deposits		fluoride
Nitrates	Ring test	Iron (II) sulfate , sulfuric acid	brown ring	nitrite	Proof of nitrate using a ring test
Nitrates	Lunges reagent	Sulfanilic acid , α-naphthylamine , zinc dust	Pink coloring	nitrite	Detection of nitrates with Lunge's reagents
Nitrites	Lunges reagent	Sulfanilic acid , α-naphthylamine	Pink coloring		Detection of nitrite with Lunge's reagents
Nitrites	Grieß's sample	Grieß's reagent	red filter paper
Permanganate		Iodide	Yellow color with intense blue to black thickness		Detection with iodide
Phosphates	Ammonium molybdate phosphate	Ammonium heptamolybdate	yellow precipitate	Sulfide, bromide, iodide, thiosulfate, tin (II)	Proof with molybdate solution
Phosphates	Ammonium magnesium phosphate	Ammonia and magnesium chloride	white precipitate		Detection with ammoniacal magnesium salt solution
Phosphates	Zirconium hydrogen phosphate	Zirconium dichloride oxide or zirconium dinitrate oxide	white precipitate		Phosphate than zirconium phosphate
Silicates	Heteropoly acid with molybdic acid	Ammonium heptamolybdate , nitric acid	yellow solution	Phosphates , arsenates
Sulfites	Manganese (II)	Potassium permanganate	Discoloration		Sulphite with permanganate
Sulfates	Barium sulfate	Barium chloride	white precipitate		Sulfate as barium sulfate
Sulphides	Hydrogen sulfide	strong acid	Rotten egg stench		Smelly sample: detection as hydrogen sulfide
Sulphides	Lead sulfide	Lead (II) acetate	Blackening		Sulphide anions with lead acetate paper
Sulfides , thiocyanates	Iodine azide reaction	Iodine , sodium azide	Discoloration, gas evolution	Excess iodide	Iodine azide reaction
Thiocyanates	Iron (III) thiocyanate	Iron (III) chloride	“Bull's blood red” color		Bull blood sample
Thiocyanates	Copper thiosulfate	Copper (II) sulphate , sulphites	initially green, black in excess, white with sulfite		Detection with copper sulfate
Thiosulfates	Silver thiosulfate , silver sulfide	Silver nitrate	white precipitate, then over yellow, orange, brown to black		sunset

Cations

connection	Evidence as / by means of	Reagents	indication	Disorder	Experiment instructions
aluminum	Cryolite	Sodium fluoride , phenolphthalein	Red color		Proof by means of a cryolite sample
aluminum	Morin paint	Morin	green fluorescence		Evidence as a fluorescent Morin lake
aluminum	Cobalt aluminate	Cobalt (II) nitrate	blue pigment		Evidence as cobalt aluminate
aluminum	Alizarin-S-color lake	Alizarin S	red precipitate	Chromium, iron, titanium	Proof as Alizarin-S-colored lake
ammonium	Cross match	Caustic soda	ammonia		Verification by cross match
ammonium	Neßler reaction	Potassium tetraiodomercurate (II)	red-brown solution		Detection by means of Neßler's reagent
antimony	Marsh's sample	Hydrochloric acid, zinc pearls, copper sulfate	pale blue flame, black mirror	arsenic	Marsh's sample
antimony	antimony	iron	black flakes		Iron nail test
antimony	Antimony (III) sulfide	Hydrogen sulfide	orange precipitate		Proof as antimony sulfide
arsenic	Arsenic (III) sulfide	Hydrogen sulfide	yellow precipitate		arsenic
arsenic	Bettendorf's sample	Tin (II) chloride	Brown color		Bettendorf's sample
arsenic	Gutzeitsche sample	Zinc , silver nitrate	Yellowing, subsequent blackening	antimony	Gutzeitsche sample
arsenic	Fleitmann's sample	Potassium hydroxide , aluminum , lead (II) acetate , mercury (II) chloride	Yellowing, gradually black	antimony	Fleitmann's sample
arsenic	Marsh's sample	Hydrochloric acid, zinc pearls, copper sulfate	pale blue flame, black mirror	antimony	Marsh's sample
arsenic	Molybdate arsenic acid	Ammonium heptamolybdate	yellow precipitate		Arsenate detection with molybdate solution
arsenic	Magnesium ammonium arsenate	" Magnesium mixture "	white precipitate
barium	Barium sulfate	dilute sulfuric acid	colorless precipitate	Calcium, strontium, lead and the like a.	s. Calcium
barium	Barium chromate	Potassium chromate	yellow precipitate	high proton conc.
Bismuth	Bismuth thiourea complex	Thiourea	yellow solution		Evidence by means of a bismuth slide
Bismuth	Bismuth iodide	Iodide	black precipitate, orange solution		Detected as bismuth iodide
Bismuth	Bismuth	Tin (II) salts	black		Evidence as bismuth
lead	Lead iodide	Iodide	yellow precipitate, colorless solution in excess		Proof as lead iodide
lead	Lead chromate	Dichromate	yellow precipitate		Detection as lead chromate
cadmium	Cadmium sulfide	Sulfide , cyanide	yellow precipitate		Evidence as cadmium sulfide
Calcium	Calcium sulfate	sulfuric acid	white precipitate	Barium, strontium	Proof as calcium sulfate
chrome	Chromate	Sodium hydroxide , hydrogen peroxide	yellow solution		Proof as chromate
Cobalt	Cobalt thiocyanato complex	Thiocyanate	pink, in amyl alcohol blue	iron	Evidence as a thiocyanato complex
Cobalt	Cobalt hydroxide	Caustic soda	blue precipitate, with excess red		Evidence as cobalt hydroxide
iron		Thioglycolic acid	Red color
iron	Berlin blue	Potassium hexacyanidoferrate (II) (yellow blood liquor salt), potassium hexacyanidoferrate (III) (red blood liquor salt)	blue precipitation	copper	Iron (II) with red blood lye salt , iron (III) with yellow blood lye salt
iron	Iron (III) thiocyanate	Thiocyanate	deep red solution	Cobalt	Iron (III) with thiocyanate
potassium	Potassium perchlorate	Perchloric acid	white precipitate		potassium
copper	Copper tetramine complex	Ammonia water	deep blue solution	nickel	Evidence as a copper tetramine complex
copper	Copper hexacyanidoferrate	Potassium hexacyanidoferrate (II)	brownish red precipitate	iron	Evidence as copper hexacyanidoferrate
lithium	Lithium phosphate	Disodium hydrogen phosphate	white precipitate
lithium	Lithium [orthoperiodato-ferrate (III)]	Potassium [orthoperiodato-ferrate (III)]	white-yellow precipitate
magnesium	Magnesone complex	Magneson	deep blue precipitation	Heavy metals, Al, Be, Ca
manganese	permanganate	Lead (IV) oxide	purple solution		Proof as permanganant
manganese	Manganese (IV) oxide	alkaline bath	brown precipitate		Detection as manganese (IV) oxide
molybdenum	Molybdophosphate	Disodium hydrogen phosphate	yellow crystals		Proof as molybdophosphate
molybdenum	Molybdenum blue	Ascorbic acid	Blue color
nickel	Bis (dimethylglyoximato) nickel (II)	Diacetyl dioxime	Red color		Proof with DAD
mercury	Amalgam sample	Copper sheet	silvery shining amalgam		Amalgan tasting
mercury	Cobalt thiocyanatomic curate	Ammonium thiocyanate , cobalt (II) nitrate	blue crystal		Evidence as cobalt thiocyanatomic curate
mercury	Hydrochloric acid group	Hydrochloric acid , ammonia	black precipitate		Detection with ammonia
silver	Silver chloride	chloride	white precipitate, soluble in ammonia		Detection with chloride solution
silver	Silver cyanide , silver (I) thiocyanate	Cyanide , thiocyanate	white precipitate, soluble in excess		Detection with cyanide or thiocyanate
silver	Silver chromate	Chromate	red-brown precipitate		Detection with chromate
titanium	Triaquohydroxooxotitanium (IV) complex	Hydrogen peroxide , sulfuric acid	yellow-yellow-orange solution	Iron , vanadium , molybdenum , chromate , fluoride
zinc	Rinman's green	Cobalt (II) nitrate	turquoise green powder		Evidence as Rinman's green
zinc	Zinc sulfide	sulfide	white precipitate		Proof as zinc sulfide
zinc	Potassium zinc hexacyanidoferrate (II)	Potassium hexacyanidoferrate (II) (yellow blood liquor salt)	white precipitate		Detection with yellow blood liquor salt
tin	Luminous test	Zinc , hydrochloric acid	blue glow		Evidence by means of a luminous sample
tin	Molybdenum blue	Molybdate	Blue color		Evidence as molybdenum blue

Organics

Anions

connection	Evidence as	Reagents	indication	Disorder	Experiment instructions
Acetates	acetic acid	Potassium hydrogen sulfate	Acetic acid odor		Acid residue anions
Acetates	Ethyl acetate / pentyl acetate	Ethanol / amyl alcohol	Glue / fruity odor		Acid residue anions
Acetates	Silver acetate	Silver nitrate	Precipitation	Halides	Acid residue anions
Acetates	acetic acid	${\displaystyle {\ce {La(NO3)3}}}$, , ${\displaystyle {\ce {KI*I2}}}$ ${\displaystyle {\ce {NH3}}}$	Blue color	${\displaystyle {\ce {PO4^3-}}}$, , ${\displaystyle {\ce {F-}}}$ ${\displaystyle {\ce {SO4^2-}}}$
Butyrate	Butyric acid or methyl butyrate	Acid or methanol + acid	odor		Acid residue anions
Tartrates	Ditartratocuprate (II)	Copper (II) salts	blue solution		Acid residue anions

Substance groups

connection	Evidence by means of	Reagents	indication	Disorder	Experiment instructions
Aldehydes , reducing functional groups	Great test	Ammoniacal silver nitrate solution	Silver mirror
Aldehydes, reducing sugars	Fehling's trial	Copper sulfate , caustic soda , potassium sodium tartrate	red copper (I) oxide	other reducing compounds	Fehling's trial
Aldehydes	Schiff's sample	Fuchsine , sulfuric acid	reddish hue
Aldehydes	Angeli Rimini reaction	Benzenesulfhydroxamic acid , ferric chloride	Red color
Aldehydes, ascorbic acid , reducing sugars	Benedict reagent	Sodium citrate , sodium carbonate , copper (II) sulfate	yellow precipitate
Aldehydes, reducing functional groups	Nylander's reagent	Bismuth salts	Brown or black color
Haloalkanes	Beilstein trial	copper	green to blue-green flame	organic nitrogen compounds
Alkenes	Alkene evidence	Bromine water	Discoloration	Phenols and many reducing compounds also discolor bromine
Alkenes , alkynes	Baeyer rehearsal	Potassium permanganate	Discoloration	Aldehydes, formic acid and its esters, phenol and aniline derivatives as well as mercaptans and thioethers
Alcohols	Lucas sample	Zinc chloride , hydrochloric acid	Cloudiness
Aldehydes , ketones	DNPH reagent	2,4-DNPH	Precipitation
Phenols	Phenol evidence	Iron (III) chloride	green-blue coloring
amino acids	Ninhydrin reaction	Ninhydrin	blue colour
Pentoses	Bial sample	Orcin , ferric chloride , hydrochloric acid	green-blue coloring
Pentoses	Dische rehearsal	Diphenylamine , glacial acetic acid , sulfuric acid	blue colour
carbohydrates	Molisch sample	α-naphthol in ethanol , sulfuric acid	purple ring
Ketohexoses	Selivanov rehearsal	Resorcinol (ethanolic solution), hydrochloric acid	red dye
Lactose , maltose , cellobiose , lactulose	Wöhlk reaction	Ammonia solution , potassium hydroxide solution	salmon red color		Wöhlk reaction
Peptide bond	Biuret reaction	Copper sulfate , caustic soda	dark purple color
aromatic amino acids	Xanthoprotein reaction	nitric acid	yellow COLOUR
Hydrogen sulfide , mercaptans	Doctor test	Sodium plumbite	brown color, discoloration

literature

• Michael Wächter: chemistry laboratory . Verlag Wiley-VCH, Weinheim 2011, pp. 215-241, ISBN 978-3-527-32996-0
• Gerhart Jander, Ewald Blasius, Joachim Strähle and Eberhard Schweda: Textbook of analytical and preparative inorganic chemistry , 16th edition, S. Hirzel Verlag GmbH & Co, Stuttgart 2006, ISBN 3-7776-1388-6 .
• Fritz Umland and Gerold Wünsch: Characteristic reactions of inorganic substances , 2nd edition, Aula-Verlag, Wiesbaden 1991, ISBN 3-89104-523-9 .
• Wilhelm Biltz, Werner Fischer and Jochen Busemann: Execution of qualitative analyzes of inorganic substances , 17th edition, Verlag Harri Deutsch, Frankfurt am Main 2001, ISBN 3-87144-816-8 .
• Eberhard Gerdes: Qualitative Inorganic Analysis , 2nd edition, Springer, 1998, ISBN 978-3-540-67875-5 .

Web links

Wikibooks: Internship Inorganic Chemistry  - Learning and teaching materials