| Launch：2019-07-26 |
* Introduction
In all kinds of economic cases and economic disputes, the perpetrators often use ink or ink to forge documents in order to escape the crime and tamper with the facts, so the detection of ink and ink is particularly important. In recent years, drug abuse, drug trafficking, drug production and other criminal activities have posed a great challenge to people's health and social stability, at the same time, the work of drug control in China has become increasingly serious. The detection of Suspects'related residues and explosive residues at some crime scenes plays an important role for public security personnel. Tracing the source of explosives can help public security personnel prevent criminal activities from the source. Raman spectroscopy as a fast, sensitive and non-destructive testing technology can be applied to the rapid detection of ink, documents, drugs, explosives, etc. It plays an important role in the field of the court.
* Application
Identification of common drugs by Raman spectroscopy
Because most of the drugs are white powder, criminals often use salt, laundry powder, sugar and other white powder to camouflage and shield drugs, causing great trouble to customs and public security personnel. Raman spectroscopy, as a kind of technology which can detect the structure and vibration energy level of substances, can detect drugs quickly.
Fig.1 Raman spectra of papaverine
Fig. 2 Raman spectra of thebaine
Fig.3 Raman spectra of cocaine
Fig.4 Raman spectra of heroin
Fig.5 Raman spectra of sucrose Fig.6 Raman spectra of starch
Most drugs have a sharp characteristic peak that can be easily distinguished from starch and so on. Moreover, Raman spectroscopy has the function of micro-analysis, which can be distinguished by Raman spectroscopy even when drugs are mixed with other powders.
Raman spectroscopy and its application in the field of evidence identification
In forensic field, identification of material evidence is very important, which directly affects the trend of judgment. Raman spectroscopy as a fast and accurate detection method can be used for identification of material evidence.
In one case, both parties submitted an equity contract, but the contents of the first two pages are different, so authenticating the documents becomes the key. Double confirm two documents printed by the same printer at the same time. The paper and the ink should be the same, and the Raman spectrum of the document will be checked.
According to the Raman spectra, the third page of the second document is consistent with the Raman spectra of the first document, but the Raman spectra of the first and second documents are obviously different from those of other documents. Later, the other side also admitted forging documents.
Raman spectroscopy has been widely used in forensic science because of its high sensitivity, few samples needed and no damage to the tested samples. It can not only detect the genuineness of drugs and documents, but also trace the source of explosives, tamper with handwriting and chronology of ink and ink. With the improvement of technology and equipment, Raman spectroscopy technology will play a greater role in the field of public security court.
Reference:
Raman spectroscopy to identify common drugs, Luning Liang, etc
Raman spectroscopy and its application in the field of physical evidence identification,Yuanyuan Lian, etc
