Quality assurance

Performance of all quality control samples (blanks, standards, internal standards, etc.) along with our clients samples, undergo a thorough review process. Blind control samples are monitored and tracked to ensure ongoing lab proficiency, as well as to identify potential points of improvement in our analytical processes.

The spike levels of various drugs are modified to accommodate the difference in sensitivities between immunoassay and direct instrumental methods. The drug concentrations utilised routinely approach the detection limit of the analytical methods. The group of QC samples for a given week may contain the following:

• One or more drugs at Direct Instrumental detection levels for serum. Instrumental detection levels for each drug are determined by limit of detection studies for the methods in use.
• One or more drugs at Direct Instrumental detection levels for urine.

Records on the performance of both the Direct Instrumental and the immunoassay screening results are monitored as part of ALS’s QA/QC program. The results are evaluated by the QA/QC Manager, Technical Director, and Chief Science Officer and any actions deemed necessary to improve the screening process are implemented as part of ALS’s Continual Improvement Program.

Proficiency testing programs –

Association of Official Racing Chemists (AORC) Program

RMTC’s External Quality Assurance Program (EQAP)

The Racing Medication and Testing Consortium accreditation requires participation in their EQAP PE program. This programs consists of acceptable performance on two (2) sets of ten (10) samples per year. The ten samples include five (5) equine urine and five (5) equine blood samples. The primary aim of the RMTC Proficiency Testing Scheme is to monitor laboratory performance and compare it with that of other RMTC accredited laboratories. The EQAP program has both qualitative and quantitative samples. The qualitative samples, satisfactory performance is based on reporting the same drug as the assigned result. For quantitative results, the results are converted into a z-score and must be within two z-values to be satisfactory.

Sample exchange programs

ALS in 2015 has initiated and manages a sample exchange program with both the University of Illinois and Texas A&M Drug Testing Laboratories for independent verification of results. Texas A&M Laboratory is RMTC accredited and the University of Illinois has interim RMTC accreditation. These split exchanged blood and urine samples are blind to our laboratory staff and are used to verify that we can reliably screen all drugs at the TOBA threshold levels.

Direct instrumental screening

Internal QC samples are added to each set of samples. A set usually consists of the samples shipped to the Lab from one day of racing. The internal QC samples are spiked, extracted and analysed along with the client samples by LC/MS or GC/MS. The purpose of the QC samples is to ensure that the drugs can successfully be identified with the instruments and methods we have in place. It is also a safeguard to make sure that data isn’t released to the clients until our quality control requirements are satisfied for each set.

Internal standards, typically deuterated standards of common drugs from different classes of drugs, are also added to samples to be screened in addition to control blood and urine samples. The recovery of the internal standards are control charted to verify that the extraction and preparation process and instrumental analysis are functioning properly.

Both matrix (blood or urine) and solvent blanks are analysed with each batch of samples. Running these blank samples verifies that no inadvertent contamination occurred during the drug extraction and preparation process.

Liquid Chromatography / Mass Spectroscopy (LC/MSn)

The LC/MS system is evaluated and calibrated using a mixture of compounds to characterise its performance. This mixture is used daily, if poor performance is suspected, or after maintenance. The daily check for the LC/MS consists of obtaining satisfactory spectra of the drug(s) being sought on the day of analysis. Confirmation of drug samples will include the quality control of drug calibration mixtures, negative and positive control samples, and appropriate solvent and system blanks.

Gas Chromatography/Mass Spectroscopy (GC/MS)

When suspect samples are submitted for GC/MS confirmation/identification, the GC/MS instrument is tuned to decafluorotriphenylphosphine (DFTPP) to validate the instrument’s proper operation, after which a solvent blank, negative and positive control samples, standard solution of the suspect drug, and the suspect sample are examined. The spectra of all samples are then examined and recorded.

Immunoassay

Five to eight wells are used for calibration standards. Quality control is monitored by analysis of standards used in each plate. These standards consist of a control negative and several standard concentration levels spiked into known blank urine. One of the QC standard levels is spiked at the threshold for the specific drug being tested. Blind quality control samples are run at a frequency of 5 to 10%. This assures that immunoassay systems meet specifications for drug detection.

High Pressure Liquid Chromatography (HPLC)

Quality control samples, at varying concentrations of the specific analytes, are analysed along with official blood or urine samples. Additionally, check standards (spiked samples) are quantitatively analysed along with official samples to verify extraction efficiency and proper instrument function. The deviation range of our check standards (at the regulatory level) for a particular analyte must be within ± 10%. These check standards are run after every 10 samples and if the acceptance criteria is not met, the samples are re-extracted and re-analysed.