THE Drug Chemistry Branch at the U.S. Army Criminal Investigation Laboratory receives samples of unknown chemicals from investigators in the field and analyzes them, attempting to identify them and determine how much of the substance is present in a sample.

'Dan Reinhardt, chief of the Drug Chemistry Branch, explained that though a chemist may be able to identify a substance, he hasn't solved the case-the special agents have to do that; the Drug Chemistry Branch just provides one of the integral pieces.

'What we're trying to do is identify, first, any controlled-substances,' Reinhardt, who has a doctorate in organic chemistry, said. There are roughly 400 compounds on the federal controlled substance list, making the chemists' job a bit daunting.

'If a chemist can't tell what a compound is from one test, they often run it through other types of tests, which may help identify the compound.

'After that we can identify a lot of the prescription drugs, which expands the whole realm. But we do that more on a case-by-case basis,' he added.

'The branch looks at about 1,200 cases a year, which is more than one third of the cases that come into USACIL, Reinhardt said. Most of the cases involve marijuana, cocaine, methamphetamines or other illegal drugs, but the branch also sees many drug-facilitated sexual assaults, and looks for alcohol or other legal and illegal substances.

'We like, at a very minimum, to have two different really strong confirmatory tests on the same exhibit, and then we'll go 'OK,'' and positively identify a substance,' Reinhardt said. 'The more tests you do, the better it gets.'

'One forensic drug chemist, Jason Nawin, demonstrated how to start processing a bulk quantity of marijuana. He was processing roughly 100 pounds of the drug, packaged in several large bales. First, Nawin had to weigh the drug. He spread brown paper on the examining table to gather anything that might fall, and then opened the bale and began to weigh the marijuana.

'The smell was overwhelming. Another chemist swept up smaller chunks of the sample that escaped to the floor. 'That's the problem you get when with bulk quantities this big-it's hard to keep things clean,' Nawin commented.

'The next step...is that I'm going to take samples from each bale-I'm going to weigh them all, take samples of them all, and then I'm going to do my analysis on it, which includes...looking (at it) through a microscope,' Nawin explained.

'Reinhardt explained that when analyzing a drug, the first thing to do is break the compound apart, to determine the structure of the compound, known as structural elucidation. The gas chromatography mass spectrometer is one of the instruments that performs the separation, and provides information on the compound.

'I blow that (compound) apart with an electron beam and pick up all the little fragments, the molecules, count them electronically, and graph them,' Reinhardt said. From there, a chemist can start to identify the substance.

'In addition to identifying unknown substances, the branch determines the quantity of some samples.

'A typical example would be, the military uses morphine injectors, so you have a solution of morphine that they use for the battlefield...say somebody gets a hold of those and takes half of the liquid out and replaces it with a saline,' Reinhardt said.

'(When) somebody in the field starts figuring out what's going on, they'll come to us,' he said. The chemists identify the morphine, but determine it's not the correct level, that half of it may be missing. 'We turn that back over to the investigator and the investigator, fortunately or unfortunately, has most of the hard work going on...I can't tell what happened, but I can tell them what it's not supposed to be.

'I just think of us as one little piece of the puzzle. With that, we also have to get the agents involved,' Reinhardt said.

'We all get one little piece of the puzzle to try to pull the whole picture together,' he said.