Creating a level playing field for athletes in competition is the raison d’etre of drug-free sport. National Anti Doping Organisations (NADOs) and sporting federations have developed appropriate programmes of testing of athletes both during events and throughout their training. Strategic and random testing programmes have been established; however adulteration of samples is common among those athletes who have been later identified of drug abuse. Sample adulteration involves product that is either ingested by the athlete or added to the sample.
Doping Control Officers (DCOs) will receive a sample of urine from the athlete under strict guidelines. The sample will be divided into two aliquots, one given to the athlete the second retained for analysis. Primary testing of the retained sample is made in the presence of the athlete that includes a colorimetric assessment, specific gravity measurement, and possibly pH measurement.
What's the problem?
Excessive ingestion of water by the athlete to dilute the concentration of the drug or its metabolites is typically used. Dilute urine is light in colour so the athlete may ingest Vitamin A & B to promote a stronger colour to the urine to avoid suspicion. Commercial products are also in use that may effect analytical measurement detection of drugs or metabolites that may be present. The measurement of urine specific gravity has until recently been measured using clinical dip sticks, which have poor accuracy, or using optical refractometers that allow measurement of the urine specific gravity. These optical devices require appropriate training to assure correct measurement and do not allow the athlete to see the observed value. In addition the instrument requires a natural light source has to be held up to the eye, which is not the most hygienic choice.
A new solution
ESSLAB now offers the Atago PAL-10s and Pen-Pro Urine digital instruments, which are becoming the method of choice for many international sports bodies and NADOs.
The instruments require just a few drops of urine to make a specific gravity reading, temperature corrected and without any intervention or adjustment by the DCO. The value may be clearly seen by the athlete, at which stage he/she may be requested to provide a further sample, under closer supervision to assure an appropriate sample is returned to the laboratory for screening. The expected Usg is 1.020. Values below this would suggest adulteration by dilution. In endurance events there is a significant level of dehydration, therefore it may also be appropriate to take a further sample 24 hours later when complete rehydration is realised.
