Chemex operates a rigorous analytical quality control (AQC) program to ensure the highest level of confidence in reported data.

At Chemex we are committed to the generation of accurate, precise analytical data of verifiable quality. Our AQC programs are designed for each batch of samples to ensure acceptable levels of precision, accuracy and representativeness to received samples. The AQC program ensures that for each analytical method appropriate quality control parameters are established, suitable monitoring regime and performance criteria are defined and achieved.

AQC parameters applied and monitored are divided into two areas of application:
- Instrument performance QC - to ensure instrument stability, selectivity and responsiveness before, during and after the analysis of a batch of samples. To ensure that, at Chemex we routinely analyse:
o Instrument Blanks
o Initial Linear Calibration standards
o Continuing Calibration Check (CCC) standards
o Every sample is spiked with internal standards to help to evaluate instrument stability and/or used for sample analyte quantitation
o Where inter-element interferences occur, Chemex applies corrections for matrix interferences (e.g. ICP-MS)
o Instrument selectivity and assignment accuracy are monitored by using characteristic ion masses checks for each target analyte of interest or by analysing extract on a confirmatory column to provide supportive evidence for any initial positive assignments
- Sample batch QC -to monitor acceptable method performance, accuracy and precision, obtain estimates of any errors, associated with each sample batch. Our laboratory routinely analyses quality control samples including but not limited to the analysis of:
o Method Blanks -to monitor laboratory contamination,
o Trip Blanks (for Volatile organics analysis) to determine sample bottle contamination during transport,
o Laboratory Control Samples using certified reference materials or spiked real matrix samples.
o Sample Duplicate analysis and Matrix Spike/ Matrix Spike Duplicates (MS/MSD) are analysed monitor accuracy and precision.
o All samples are spiked with surrogate compounds in order to evaluate method recovery efficiency.

Chemex Quality Assurance programme include plotting of AQC data on control charts in order to monitor the performance of analytical methods and equipment vital to the provision of accurate and precise data. Statistically derived action and warning limits are assigned to each parameter that represent the acceptable level of precision of the method. Any failures or trends are investigated and corrective actions assigned and addressed to improve the performance.

Quality Assurance data are available upon request for any project or report. Chemex has several types of data presentation packages designed to meet a variety of reporting requirements. Our QC packages are outline in section Data Reporting.