Specimen food ingestion

Examples of subversive false positives for urinalysis are positives caused by the ingestion of food or drink that has been spiked with a drug or by the willful contamination of urine specimens. It is essentially impossible to detect such subversive activities in the case of urinalysis however, we will show that they are readily detected by hair analysis. Although subversive activities may be a rare occurrence, they cannot be ignored since they are frequently used as challenges to a positive urinalysis result (the "brownie" defense). 

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