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Ehrlich's reagent
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<h2 id="medical-testing">Medical testing</h2> <p>Ehrlich reagent can be used to detect <a href="/facts/Urobilinogen/XNrgPqpb">urobilinogen</a>, which can indicate <a href="/facts/Jaundice/TCyoLMJU">jaundice</a> or other <a href="/facts/Liver/Rtp4Fk2b">liver</a>-related issues. </p><p>A very common Ehrlich test is a simple <a href="/facts/Spot_analysis/3jQIXhak">spot test</a> to identify possible <a href="/facts/Psychoactive_drug/dNXrUmsx">psychoactive</a> compounds such as <a href="/facts/Tryptamine/5G31m4BT">tryptamines</a> (e.g. <a href="/facts/N%2cN-Dimethyltryptamine/oIPCXryU">DMT</a>) and <a href="/facts/Lysergamide/rPrQfVvF">lysergamides</a> (e.g. <a href="/facts/LSD/o5qq0grH">LSD</a>). It gives a negative test-result for <a href="/facts/25I-NBOMe/eA2kwDRN">25I-NBOMe</a> and many other non-indole-related psychoactives. The reagent will also give a positive result for <a href="/facts/Opium/JzHUtced">opium</a>, because of the presence of <a href="/facts/Tryptophan/JcUxlxAh">tryptophan</a> in natural opium.<a class="footnote-ref" id="fnref:2" href="#fn:2"><sup>2</sup></a> </p><p><a href="/facts/Pyridoxine/sRTLFpv1">Pyridoxine</a>, present in <a href="/facts/Vitamin_Supplements/IfC33Tm9">vitamin supplements</a>, can give positive results to the Ehrlich test, showing a pink colour change.<a class="footnote-ref" id="fnref:3" href="#fn:3"><sup>3</sup></a> </p> <h2 id="preparation">Preparation</h2> <p>The reagent is prepared by dissolving 0.5<a class="footnote-ref" id="fnref:4" href="#fn:4"><sup>4</sup></a>–2.0 g of <i>p</i>–dimethylaminobenzaldehyde (DMAB) in 50 mL of 95% <a href="/facts/Ethanol/3lCLfBSP">ethanol</a> and 50 mL of concentrated <a href="/facts/Hydrochloric_acid/HqItJlUT">hydrochloric acid</a><a class="footnote-ref" id="fnref:5" href="#fn:5"><sup>5</sup></a><a class="footnote-ref" id="fnref:6" href="#fn:6"><sup>6</sup></a> and is best used when fresh. Other alcohols, such as <a href="/facts/1-propanol/NoSmhEhh">1-propanol</a>, can also be used as well.<a class="footnote-ref" id="fnref:7" href="#fn:7"><sup>7</sup></a> </p><p>The Ehrlich reagent is similar to a number of other indole tests: </p> <ul><li>The van Urk reagent, which uses 0.125 g of p-DMAB, 0.2 mL of <a href="/facts/Ferric_chloride/a51pulq1">ferric chloride</a> solution (25 mg/mL) in 100 mL of 65% <a href="/facts/Sulfuric_acid/Wom6fymJ">sulfuric acid</a>.<a class="footnote-ref" id="fnref:8" href="#fn:8"><sup>8</sup></a><a class="footnote-ref" id="fnref:9" href="#fn:9"><sup>9</sup></a><a class="footnote-ref" id="fnref:10" href="#fn:10"><sup>10</sup></a> This is sometimes referred to as the Hofmann reagent or p-DMAB-TS (Test Solution) and gives slightly different colours with different indoles.</li> <li>The <a href="/facts/Renz_and_Loew_reagent/8IkzvknH">Renz and Loew reagent</a>, which uses <a href="/facts/P-dimethylaminocinnamaldehyde/8IkzvknH"><i>p</i>-dimethylaminocinnamaldehyde</a> and may also be used for the detection of flavonoids.</li> <li>The "improved hallucinogen reagent", which uses a 1:1 solution of 5% DMAB in concentrated <a href="/facts/Phosphoric_acid/l6NbwyCv">phosphoric acid</a> (specific gravity 1.45) to <a href="/facts/Methanol/EIfpoNCg">methanol</a>.<a class="footnote-ref" id="fnref:11" href="#fn:11"><sup>11</sup></a><a class="footnote-ref" id="fnref:12" href="#fn:12"><sup>12</sup></a></li></ul> <h2 id="see-also">See also</h2> <ul><li><a href="/facts/Drug_checking/lFM6GmRD">Drug checking</a></li> <li>Other alkaloid spot tests: <ul><li><a href="/facts/Froehde_reagent/Jfh19wPq">Froehde reagent</a></li> <li><a href="/facts/Indole_test/D0zbNUqf">Indole test</a></li> <li><a href="/facts/Kovac%2527s_reagent/hDCSMoJL">Kovac's reagent</a>, similar but uses <a href="/facts/Isoamyl_alcohol/dqKX0Hn0">isoamyl alcohol</a></li> <li><a href="/facts/Liebermann_reagent/E1If8eoF">Liebermann reagent</a></li> <li><a href="/facts/Marquis_reagent/jmn0nQtz">Marquis reagent</a></li></ul></li></ul> <h2 id="references">References</h2> <ol> <li id="fn:1"><p>Kovar, Karl-Artur; Laudszun, Martina (February 1989). "Chemistry and Reaction Mechanisms of Rapid Tests for Drugs of Abuse and Precursors Chemicals" (PDF). UNODC. p. 15. Retrieved 3 January 2016. <a href="https://www.unodc.org/pdf/scientific/SCITEC6.pdf" target="_blank">https://www.unodc.org/pdf/scientific/SCITEC6.pdf</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li> <li id="fn:2"><p>de Faubert Maunder, MJ (1975). "Field and laboratory test for raw and prepared opium". Bulletin on Narcotics. 27 (1): 71–6. PMID 1039285. <a href="http://www.unodc.org/unodc/en/data-and-analysis/bulletin/bulletin_1975-01-01_1_page008.html" target="_blank">http://www.unodc.org/unodc/en/data-and-analysis/bulletin/bulletin_1975-01-01_1_page008.html</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li> <li id="fn:3"><p>"Pyridoxine Monograph for Professionals". Drugs.com. Retrieved 2021-08-21. <a href="https://www.drugs.com/monograph/pyridoxine.html" target="_blank">https://www.drugs.com/monograph/pyridoxine.html</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li> <li id="fn:4"><p>Spratley, Trinette (2004). "Analytical Profiles for Five "Designer" Tryptamines" (PDF). Microgram Journal. 3 (1–2): 55. Retrieved 2013-10-09. <a href="http://www.erowid.org/library/periodicals/microgram/microgram_journal_2005-1.pdf#page=54" target="_blank">http://www.erowid.org/library/periodicals/microgram/microgram_journal_2005-1.pdf#page=54</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></p></li> <li id="fn:5"><p>O’Neal, Carol L; Crouch, Dennis J; Fatah, Alim A (April 2000). "Validation of twelve chemical spot tests for the detection of drugs of abuse". Forensic Science International. 109 (3): 189–201. doi:10.1016/S0379-0738(99)00235-2. PMID 10725655. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></p></li> <li id="fn:6"><p>"Color Test Reagents/Kits for Preliminary Identification of Drugs of Abuse" (PDF). Law Enforcement and Corrections Standards and Testing Program. July 2000. Retrieved 2011-07-24. <a href="https://www.ncjrs.gov/pdffiles1/nij/183258.pdf" target="_blank">https://www.ncjrs.gov/pdffiles1/nij/183258.pdf</a> <a href="#fnref:6" class="footnote-back-ref">↩</a></p></li> <li id="fn:7"><p>"Ehrlich's Reagent Safety Data Sheet" (PDF). Labchem. 2 July 2014. Retrieved 11 January 2015. <a href="http://www.labchem.com/tools/msds/msds/LC14080.pdf" target="_blank">http://www.labchem.com/tools/msds/msds/LC14080.pdf</a> <a href="#fnref:7" class="footnote-back-ref">↩</a></p></li> <li id="fn:8"><p>Ehmann, A. (1977). "The van URK-Salkowski reagent — a sensitive and specific chromogenic reagent for silica gel thin-layer chromatographic detection and identification of indole derivatives" (PDF). Journal of Chromatography A. 132 (2): 267–276. doi:10.1016/S0021-9673(00)89300-0. PMID 188858. 2.03 g FeCI3. 6 H2O were dissolved in 500 ml water and 300 ml conc. H2SO4 <a href="https://erowid.org/psychoactives/testing/testing_field_article2.pdf" target="_blank">https://erowid.org/psychoactives/testing/testing_field_article2.pdf</a> <a href="#fnref:8" class="footnote-back-ref">↩</a></p></li> <li id="fn:9"><p>Sunshine, Irving (1969). Handbook of analytical toxicology. Chemical Rubber Co. p. 408. p-DMAB-TS: To a cool soln of 65 ml H2S04 in 35 ml H2O, add 125 mg para-dimethylaminobenzaldehyde, dissolve, add 1-2 drops of FeCI3-TS. <a href="https://books.google.com/books?id=AEprAAAAMAAJ&q=%2522p-DMAB-TS%2522" target="_blank">https://books.google.com/books?id=AEprAAAAMAAJ&q=%2522p-DMAB-TS%2522</a> <a href="#fnref:9" class="footnote-back-ref">↩</a></p></li> <li id="fn:10"><p>"Basic Tests for Pharmaceutical Substances: 5. Reagents". WHO: Essential Medicines and Health Products Information Portal. Archived from the original on October 25, 2015. Retrieved 2019-12-20. <a href="https://web.archive.org/web/20151025191221/http://apps.who.int/medicinedocs/en/d/Jh1803e/6.html" target="_blank">https://web.archive.org/web/20151025191221/http://apps.who.int/medicinedocs/en/d/Jh1803e/6.html</a> <a href="#fnref:10" class="footnote-back-ref">↩</a></p></li> <li id="fn:11"><p>de Faubert Maunder, MJ (1975). "Field and laboratory test for raw and prepared opium". Bulletin on Narcotics. 27 (1): 71–6. PMID 1039285. <a href="http://www.unodc.org/unodc/en/data-and-analysis/bulletin/bulletin_1975-01-01_1_page008.html" target="_blank">http://www.unodc.org/unodc/en/data-and-analysis/bulletin/bulletin_1975-01-01_1_page008.html</a> <a href="#fnref:11" class="footnote-back-ref">↩</a></p></li> <li id="fn:12"><p>Maunder, M. J. de Faubert (August 1974). "A field test for hallucinogens: further improvements". Journal of Pharmacy and Pharmacology. 26 (8): 637–638. doi:10.1111/j.2042-7158.1974.tb10677.x. PMID 4155730. S2CID 97915487. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:12" class="footnote-back-ref">↩</a></p></li> </ol>