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The new R-3000 portable Raman
spectrometer
Explosives Identification with a
Portable Raman
80 explosives’ spectra database
Almost any scientific achievement or development whose initial idea is to help mankind can be changed into a weapon that can destroy it. As history shows, some chemicals once discovered as useful dyes or medicines, were eventually re developed as powerful explosives and many are now considered to be prohibited substances. According to the research of the Institute for Economics and Peace in collaboration with University of Maryland, during past 10 years only 31 countries (from 158 being examined) have not experienced terrorism. The US department of States reports about 10 000 terrorist attacks and over 12.5 thousand people killed in 2011 alone. And this is why rapid and precise identification of explosives is becoming one of the main tasks for homeland defense / security and has become particularly more relevant with the introduction of portable Raman systems. Each air passenger _____ RDX flying from one country to another will know that it is not allowed to carry more than 100 ml of liquid substance in hand luggage. This situation would not exist if security services was able to identify precisely the content of our bottles and be sure that it is only water or medicine inside, not an explosive or its components. On the other hand, it is possible to construct a very dangerous liquid bomb by combining liquids from three 100 ml bottles. From this point of view it would be even more interesting to identify the contents of all bottles in hand luggage, although such a procedure would certainly lead to a “bottle neck“at the security desk. It’s always a problem for both the police and military personnel to check in situ whether a person is carrying a dangerous substance or not. Should they even spend time on such checks when an unknown substance might turn to be simple soda, sugar or glycerine? Positive laboratory examinations can take several days, and the side effects for innocent travelers must be taken into consideration. In either situation our latest range of hand held and portable compact Raman Analyzer will become an invaluable support tool with its ability to instantly detect explosives and its components contained In standard see thru packages. R3000 Raman for Explosives Identification In 2013 the R3000 using an Enspectre grating spectrograph was tested by a leading forensics center specializing in explosives and other prohibited substances'. During the time of these measurements about 80 spectra of common and dangerous explosive substances were acquired and now form a reference database, containing precise Raman spectra all using 532nm laser excitation (conditions for measurements were: 75‐1000ms exposure time and 100 acquisition cycles). See above the spectrum of RDX now included in our unique data base. To verify the instrument’s functionality and applicability for quick and accurate analysis, we analysed 17 unknown solid and liquid explosives all of which were to be identified under controlled laboratory conditions with time limits. The samples (quantity ≤ 50mg) were identified for 0.075‐3s accumulation time for each sample. 100% of the samples were identified correctly. These results were achieved due to the unique features of our 532nm Raman technology  High spatial resolution 20µm allows measuring 10‐5g of substance without a sample stage and less than 10‐6g with a sample stage  Ultimate safety: Our laser excitation at 532nm is used at just 12mW, which is safer for the operator and ensures that explosive substances do not detonate or burn. If there is no danger of detonation or burning it is possible to increase the laser power to 30mW and vice versa ‐ decrease the power if there is such a danger. Usually it is not a problem since most explosives have very strong Raman spectra  Rapid analysis: time per measurement < 3 seconds  Superb sensitivity: Even with a laser power of 12mW Our unique Raman system will acquire a perfect spectrum from a substance with high speed and excellent S:N. Most of our competitors can hardly obtain such a spectrum even with 250‐500mW lasers for 1 second, which in any case is much more dangerous.  Data transmission via Bluetooth: this option is complimentary and will guarantee additional security for the user  Portability: optional in‐built battery supports over 6 hours of off‐line operation an From the following spectra you will see that we have achieved truly excellent results during the analysis using instrument with just a vial holder and coverslip holder. Methodology For identification of 14 samples we placed them in vials (quantity ≤ 50mg) and used a standard 1s acquisition time. Sample handling and analysis was relatively simple and the measurement and analysis of each sample taken through through the vial took only 5s or so. Due to a specific form and size of some solids (as shown in the picture with a vial), 3 of 17 substances were positioned between two cover glass windows in a coverslip holder and measured. Below is an example of one sample that was measured using a simple coverslip holder. Step 1: Place a cover glass into the sample holder attachment and place a sample over the hole Step 2: Cover accurately with a second cover glass Step 3: Make sure that the sample is placed correctly Step 4: Carefully twist a cover in place for the holder 1 3
2 4
Using coverslip holder and cover glass for explosives’ measurement Measurements 2,4,6‐Trinitrotoluene (TNT) State: Powder Molecular Formula: C7H5N3O6 TNT is commonly used for military and industrial applications and is valued because of its insensitivity to shock and vibration, which reduces the risk of accidental detonation. The historical fact is that TNT was first prepared in 1863 by the German chemist Julius Wilbran and originally used as a yellow dye. During the measurement we were unaware of the type of sample being analysed. The control Laboratory was therefor extremely surprised with how fast the analysis was completed and verified (1s exposure time, 1 acquisition cycle), clear (0.959 correlation with database) and just how easy the identification of a small amount of explosive powder could be through the vial window. The comparison of the acquired spectrum of TNT with the reference one shows the high quality of such a fast measurement. The spectrum below was taken with 100 acquisition cycles against 1 cycle for the one above: the quality of spectrum is obvious. 2,4,6‐trinitrotoluene 1,3,5‐
Trinitro‐
1,3,5‐Triazacyclohexane (Hexogen, RDX) State: Powder Molecular Formula: C3H6N6O6 The 1993 the Bombay bombings were the first serious terrorist attacks in Mumbai India in which RDX was used by placing it into several vehicles as bombs. Outside of military applications, RDX is also used as an explosive for controlled demolition to raise building structures. Hexogen (RDX) with different plasticizers were identified correctly in the vials #15 and 16. Only 125ms were required to accurately detect RDX in sample #15. The samples of RDX #15‐16 were produced in different countries, and different substances were used to plasticize the material. Fortunately most of the explosives gave a strong Raman spectrum so much so that the instrument was easily able to determine them among other substances. Spectrum of RDX (sample #15) acquired within 125ms
Spectrum of RDX (sample #16) acquired within 500ms
1,3,5,7‐Tetranitro‐1,3,5,7‐Tetraazacyclooctane Molecular Formula: C4H8N8O8 (HMX, Octogen, Homocyclonite, HW 4) State: Powder During World War II, under the code name Aunt Jemima, HMX was mixed with flour and used by Chinese guerrillas to disrupt the Japanese invasion and occupation of China. The mixture could easily pass for regular flour. It could even be cooked into pancakes without exploding and eaten without poisoning anyone. Uneaten pancakes or unused dough could still be used later for its original explosive purposes. Octahydro‐1,3,5,7‐tetranitro‐1,3,5,7‐tetrazocine Molecular Formula: C7H5N5O8 (Tetryl) State: Powder Tetryl is a sensitive secondary high explosive used as a “booster”, a small charge placed next to the detonator, in order to propagate detonation into the main explosive charge. 2,4,6‐Trinitrophenol (Picric Acid, Shimose, Melinite) Molecular Formula: C6H3N3O7 State: Powder The reaction of Picric acid is highly exothermic and careful temperature control is required. In the early 20th century, picric acid was stocked by pharmacies as an antiseptic and as a treatment for burns, malaria, herpes, and smallpox. 1,2‐ethanedioldinitrate (EGND, Ethylene glycol dinitrate) Molecular Formula: C2H4N2O6 State: Powder EGDN was used in manufacturing explosives to lower the freezing point of nitroglycerin, in order to produce dynamite for use in colder climates. 1,5‐Dinitronaphthalene State: Powder Molecular Formula: C10H6N2O4) 1,5‐Dinitronaphthalene is an intermediate for dyes (e.g. naphthazarin and naphthalenediamine), and is used in the munitions industry as a component in the formulation of nitrate explosives. 1H‐Tetrazole (Tetrazole) State: Powder Molecular Formula: CH2N4 Although tetrazole is used for its explosive or combustive properties, sometimes tetrazole is used as a component of gas generators in automobile airbags. While measuring tetrazole, we demonstrated excellent sensitivity (75ms and 1 acquisition cycle for identification). Nitrotriazolone (NTO) State: Solid Molecular Formula: C2H3N4O3 Nitrotriazolone is a commercially available explosive, and is also used in automobile airbags as an alternative to lead azide. It is also being studied in military applications as a component for insensitive high explosives. 2,4,6‐Trinitrobenzene‐1,3‐diol Molecular Formula: C6H3N3O8 (Styphnic acid, Trinitroresorcine, 2,4,6‐Trinitroresorcinole) State: Solid Styphnic acid is used in the manufacture of dyes, pigments, inks, medicines, and explosives such as lead styphnate. It has a low sensitivity, similar to picric acid, but explodes upon rapid heating. Benzofuroxan State: Liquid Molecular Formula: C6H4N2O2 Benzofuroxan is used as an explosive in the fixed charges for detonators. The successful and rapid measurement of this and the following liquid explosive demonstrates that our unique Raman systems might well become an essential analyser for the examination of liquids at airports. Nitrobenzene State: Liquid Molecular Formula: C6H5NO2 The production of nitrobenzene is one of the most dangerous processes conducted in the chemical industry because of it reacts exothermicaly. Redistilled, as oil of mirbane, nitrobenzene has been used as an inexpensive perfume for soaps. Dinitroxydiethylnitramine (DINA) State: Liquid Molecular Formula: C2H4N4O8 DINA is relatively stable, but may be detonated by significant shock, or percussion – it is easily detonated by primary explosives. 3‐Nitrooxy‐2,2‐bis(nitrooxymethyl)propyl nitrate Molecular Formula: C5H8N4O12 (Pentaerythritol tetranitrate, PETN, TEN, Corpent) State: Powder PETN is very difficult to detect because it has a very low vapor pressure at room temperature; many times PETN bombs could not be detected by X‐ray screening or trained sniffer dogs. On the other hand, nearly pure PETN is used as a vasco dillation drug to treat certain heart conditions, such as for the management of angina. The PETN spectrum below was measured within 125ms, nevertheless the correlator for recognition differs just slightly (0,831 against 0,834). www.spectrolab.co.uk