 | |
| Names | |
|---|---|
| Preferred IUPAC name (2E,4E)-5-(4-Nitrophenyl)penta-2,4-dienal | |
| Identifiers | |
| |
3D model (JSmol) | |
| ChemSpider | |
| UNII | |
| |
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| Properties | |
| C11H9NO3 | |
| Molar mass | 203.197 g·mol−1 |
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |
Nitrophenyl pentadienal,nitrophenylpentadienal,NPPD, orMETKA (Russian for "mark") colloquially known as "spy dust",[1] is a chemical compound used as atagging agent by theKGB during theCold War Soviet Era.Soviet authorities inMoscow tracked Americans by applying an almost invisible powder to their clothing, cars, doorknobs and other objects. Some other variants of "spy dust" may have containedluminol and would glow underultraviolet light.[2][3][4]
Spy dust was first discovered inEngland in the 1930s.[5]
It was first revealed to theCentral Intelligence Agency in Moscow in 1963 byAlexander Chrepanov, a KGBwalk-in agent.[4]
Spy dust was detected in the Soviet Union in 1970s in tiny quantities.
In 1984, KGB officerSergei Votontsov (Code name GT/COWL) provided a sample of the substance.[4]
Soviet defectorVitaly Yurchenko confirmed the chemical.[4][6]
In the summer of 1985 the powder began to appear in Moscow in much larger quantities. Concerned about the health effects of the substance, theUnited StatesState Department publicly protested to the Soviets. It was later determined that the health threat was low.[7][8][9]
Beginning about 2005-2015, a chemical tracking kit for law enforcement agencies was developed using NPPD.[10] To detect NPPD a 0.1%methanol solution ofnaphthoresorcinol is added to a swab of the item in question and then concentrated hydrochloric acid is added. The observation of a red color indicates a positive test.[11] Naphthoresorcinol was frequently used in early organic chemistry investigations to determine the presence ofaldehyde groups in solution; a redadduct is formed in acidic solution.[12]
