SimpleLab Quality Assurance and Quality Control

SimpleLab delivers trusted, sophisticated lab testing with advanced health sciences and engineering support. To maintain consistency and dependability with rapid service, we have implemented essential quality assurance and control measures. These cover test ordering, kit packaging and fulfillment, shipping, sampling protocol, lab analysis accuracy, and results reporting.

Table of Contents:

• Method Blank
• Laboratory Duplicate
• Laboratory Control Sample
• Matrix Spikes
• Calibration Blank
• Calibration Standards
• Sources of Variability and Inaccuracy
• Questions? Contact Us

Quality Control Sample Processes

The quality control (QC) process is the final step that must occur before results can be verified and released in a final report. The QC process detects, evaluates, and corrects any errors due to instrumentation issues, environmental conditions, or technician performance — all before the results are reported. 

A major part of the QC process for any lab involves analyzing an array of additional samples beyond just the sample of interest.[1] Different labs may have slightly different QC processes and processes will vary by matrix, but some of the typical QC samples a lab may run include the following:

Method Blank (MB)

A method blank is a sample that is contaminant-free (e.g., laboratory grade deionized water) and is prepared and analyzed following the same process as the other samples that are being tested. This means that any preservatives or reagents used in sample preparation are added to the method blanks as well. 

Method blanks are used to determine whether the sample preparation process and any chemicals used therein introduce contaminants to the samples. If the sample results for any method blanks are anything other than non-detect, it could mean that contamination was introduced via the sample preparation process.

Laboratory Duplicate (LD)

A laboratory duplicate is created by splitting a sample into two sub-samples and analyzing them separately on the same instrument and in the same analytical batch. The results for laboratory duplicates are compared in order to evaluate the precision of the analysis.

Laboratory Control Sample (LCS)

A laboratory control sample is composed of a contaminant-free matrix (e.g., laboratory grade deionized water, as with method blanks) to which known concentrations of the target analytes have been added prior to sample preparation and analysis. The recoveries of the target analytes in the LCS are used to determine whether the method is working properly and if the lab is capable of making unbiased measurements. 

Labs set acceptance criteria for the different analytes in the LCS using statistical methods on historical data.

Matrix Spikes (MS)

Matrix spikes are similar to LCS’s in that they are samples to which known concentrations of target analytes have been added prior to sample preparation and analysis. The difference between a matrix spike and an LCS is that the analytes are spiked into the actual sample matrix for the matrix spike (e.g., the actual water, soil, etc. being analyzed), whereas an LCS involves spikes in a contaminant-free medium (e.g., deionized water). 

Matrix spikes are analyzed to confirm method performance by measuring the effects of interferences caused by the specific sample matrix.

Calibration Blank (CB)

A calibration blank is an aliquot of a contaminant-free matrix, such as deionized water, that can be used to calibrate the analytical instrument. The calibration blank is distinct from the method blank because it is not subject to the sample preparation steps used to process actual samples like the method blank. 

Calibration Standards (CS)

Calibration standards are made by diluting a standard solution containing known amounts of the target analytes, resulting in a sequence of samples with different, known concentrations of the analytes to be measured. The calibration standards (including the blank) are used to calibrate the analytical instrument.

The additional QC samples described above are just a subset of the extensive QC protocols a lab follows in order to verify results. All QC protocols are critical to ensure high quality, accurate data. If any QC checks fail, it may mean that the sample needs to be re-run, re-processed or re-collected. 

SimpleLab always strives to provide you with your results ASAP while maintaining best practices so that you can trust that your results are accurate.

Sources of Variability and Inaccuracy

Like all lab testing, results are subject to sources of variability and inaccuracy that we work to understand, explain, and limit. Here are the most common sources of variability that may affect results for informational, non-compliance SimpleLab Reports:

• Sampling time may not capture all contaminants over the course of a day
• Sampling date may not capture all contaminants over the course of a year
• Sampling location may not capture all contaminants (or may miss the contamination entirely) 
• Sample matrix may be heterogenous and even samples taken at approximately the same time and location may differ

Here are the most common sources of inaccuracy that may affect results for informational, non-compliance SimpleLab Reports:

• Accidental contamination by the sampling party or foreign material in the vicinity
• Errors during sample preparation or analysis as a result of mistakes or instrumentation issues
• Shipping of samples may result in longer hold times than recommended, or sample temperatures outside of the recommended range upon laboratory arrival

All methods used in the lab are subject to inherent sources of inaccuracy, which labs work hard to minimize with proper machine maintenance, regular calibration, and by following the QC procedures outlined in the analytical methods and laboratory standard operating procedures (SOPs).

Questions? Contact Us!

If you have questions about the accuracy of a specific testing method or result, please contact us (hello@gosimplelab.com) and we’ll be happy to provide further details depending on your analyte and method in question.