The ABCs of narcotics field testing
Improve accuracy, sample integrity and officer safety using advanced drug detection kits
Sponsored by Field Forensics
By Laura Neitzel, Police1 BrandFocus Staff
When a police officer undertakes a suspect search or arrest on the grounds of possession of illegal narcotics, that officer needs to be confident that the lab results confirm that the substance in question is exactly what they suspected.
Having long provided chemical and explosive-detection technology to U.S. special operations forces and other government agencies, Field Forensics has, for the last several years, merged easy-to-use military-technology with DOJ-approved drug reagents to provide accurate and safe narcotics identification kits to law enforcement agencies.
“We’re trying to simplify what the police have to do to get either an appropriate sample that’s easy to preserve, or to get a presumptive result in the field that can be easily supported by work that’s done in the laboratory later,” said Craig Johnson, founder of Field Forensics.
Less time leaves less room for error, he says, so the kits are designed to yield quick and accurate results.
“The longer the chain is from the time a sample is extracted in the field to the time it’s analyzed in a lab, the more probability there is for error,” said Johnson, “whether it’s systematic error or just individual error, random error or loss of sample.”
Field Forensics’ portable drug test kits for law enforcement help ensure samples tested in the field are tested accurately, safely and can stand up as presumptive evidence in court.
The Scientific Working Group for the Analysis of Seized Drugs recommends minimum standards for the forensic examination of seized drugs. SWGDRUG classifies identification techniques into three categories based on their power to discriminate among substances. Each classification has its particular benefits, uses and limitations.
Category C: Quick, low-cost color matching
Category C techniques includes colorimetric analysis, a presumptive testing method that determines the presence or absence of a substance in a sample based on the color produced by a chemical reaction when the sample is exposed to a color reagent. This is the most common method used by police officers in the field to test for specific substances.
Field Forensics’ DABIT test kits fall into this category. In under two minutes, officers can use a DABIT kit to identify a broad range of illicit narcotics, including cocaine, opiates, LSD, methamphetamines, crack and marijuana, and the test can differentiate marijuana from hemp. The kit is self-contained, and the sticky tip on the collector makes it simple and safe to collect a sample and drop it safely back into the tube. A color match indicates a positive identification.
Quick and inexpensive, Category C colorimetric testing is a good choice for officers in the field who are dealing with fairly simple substances. But when it comes to substances like fentanyl, with frequent changes to its chemical formulation, colorimetric testing may not be able to make a positive identification.
“They’re almost designer drugs in a way because you can change them a little bit and you get the same effect with varying degrees of power or narcotic effect, but very different molecules,” said Johnson. “So different sorts of test kits may or may not respond to all these derivatives of fentanyl.”
Field Forensics has a solution for this by combining colorimetric analysis from Category C with a more powerful technique from Category B. Combining techniques from different categories is a best practice recommended by SWGDRUG and provides a much stronger analytical capability than using one method alone.
Category B: Added accuracy
The Fen-Her test kit uses thin-layer chromatography for greater accuracy and officer safety.
Category B consists of intermediate analysis techniques, including thin-layer chromatography. Chromatography is used to separate substances into their component compounds.
For the Fen-Her Model DXC-002 test kit, Field Forensics combines colorimetric analysis, Category C, along with Category B thin-layer chromatography to get a more accurate test in one compact, pocket-sized kit. Using tests on a sample from different Categories is an important SWGDRUG recommendation.
Fen-Her separates components of a sample by both color and location. Heroin and fentanyl are clearly differentiated from each other by both color and location – not just from each other but from other color-producing components that might be in a typical street sample. This leads to a more accurate test by reducing false positives and helps eliminate confusion between substances. Also, Fen-Her tests for fentanyl derivates, of which there are many.
The Fen-Her kit is also safer for officers to use. Colorimetric analysis alone requires a visible amount of a sample like fentanyl or heroin for bulk identification, putting officers and K-9s at risk of overdose should they be exposed. But because the Fen-Her kit needs only a trace amount of a substance – less than a microgram – samples can be taken from residue on paraphernalia such as spoons, pipes and edges of plastic bags.
“We can do testing for fentanyl and heroin at trace levels. So, generally speaking, the officer doesn’t even need to open a bag of white powder,” said Johnson. “You can just sample along the seal of it.”
Category A: Chemical “fingerprints”
Category A techniques are the most powerful in their ability to discern the molecular structure of a substance. SWGDRUG requires Category A to be used in conjunction with another technique from any of the three categories to positively identify the presence of an illicit substance.
Raman spectroscopy measures the unique spectral fingerprint of a chemical and matches it to the spectral fingerprints of a known substance. Field Forensics’ HandyRam II hand-held Raman analyzer is a Category A technique that can be used in the patrol car to verify initial findings of the DABIT or Fen-Her kit. By measuring the unique spectral fingerprint of a chemical and finding its match in Field Forensics’ extensive spectral library, the HandyRam II can confirm the identity of a wide range of substances, including illicit narcotics, controlled drugs and pharmaceutical ingredients, as well as explosive materials and other unknown substances.
A key benefit of using the HandyRam II is that it preserves the molecular integrity of the sample so it can be preserved as evidence.
“A chemical test like a colorimetric test kit is destructive, so if you use a colored test kit on some cocaine, that stuff is no longer cocaine when you’ve mixed it with the chemical reagent,” said Johnson. “But if you look at that same cocaine with a Raman spectrometer, it’s still cocaine afterward. It doesn’t destroy it.”
While the HandyRam II may be more accurate, the cost compared to the DABIT or Fen-Her kits can restrict the number of units a department may have in use. In most situations, an officer will do a presumptive test using the DABIT or Fen-Her kits and then use the HandyRam II to confirm the field test prior to making an arrest.
“It’s not until that material is reanalyzed in the laboratory that it becomes an official result that would be used in court,” said Johnson, “so we want to make sure that when a police officer is using one of our products, the results that they get in the field are backed up by the result obtained in the laboratory. This protects both the police officer and the civilian and gives the justice system an accurate result.”