( Results and Discussion Cal...)Simultaneous Screening of 23 Drugs of Abuse in Oral Fluid Using an LC/MS/MS Method

Calibration samples at or below current established cut-off levels were provided by Leeds Teaching Hospitals NHS Trust. The following data were generated from these calibration samples as well as patient samples kindly provided by Leeds Teaching Hospitals NHS Trust

Comparison with Current Methods

The following figures summarize the ability of the method to detect concentrations of the drugs of abuse described earlier at levels at or significantly below current established cut-off levels.

Fig. 1 shows a selection of opiates at 1 ng/ml in an oral fluid matrix. This is equivalent to approximately 10 times less than the current cut-off level.*

Figure 2 shows a range of benzodiazepines at 1 ng/ml in oral fluid matrix. This is equivalent to the current established cut off level.*

Multiple Compound Screening

As the method presented in this research study allows the screening of multiple compounds from various classes, it is possible to detect the presence of abused drugs in the presence of prescribed drugs. Figure 4 shows a patient sample with a large signal for methadone. However, smaller signals for morphine, codeine and 6-monoacetyl morphine can also be seen at levels above the cut-off.* The detection of 6-monoacetyl morphine is of particular significance, as it is a primary product from the metabolism of heroin.

Multi-compound screening also makes it possible to look at various drug metabolites. This gives further credence to suspected positive results by monitoring for the major metabolite. Figure 5 shows an actual patient sample, once again with a high methadone result. In this case, however, the sample also shows positive results for cocaine and for benzoylecgonine, a cocaine metabolite.

Another potential application for multi-compound screening
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