How to remove variability and interferences in complex biological sample analysis

Complex biological samples, such as plasma, contain a significant number of proteins and lipids and are subject to variability in factors such as viscosity and amounts of debris. Sample preparation is an important aspect of biological sample analysis to achieve less variable and more consistent outcomes.

Complex biological sample analysis

Liquid or gas chromatography coupled with mass spectrometry is a powerful tool often used for biological sample analysis. However, the ionization processes involved within these techniques are complex and subject to interferences from components in biological matrices. Unwanted matrix components can create blockages and contamination issues within the instrument. These issues have cost and time implications associated with troubleshooting, instrument repair, and maintenance. Contaminants and interferences can also lead to increased baseline noise and overall lower sensitivity due to ion suppression. Both qualitative and quantitative results then become unreliable and difficult to evaluate, with poor peak shapes co-elutions and ion enhancement/suppression

Consistent sample preparation ensures cleanliness for more consistent biological sample analysis. Fewer interferences in the final sample results in a cleaner chromatogram for easier and more reliable data analysis. The challenge that many scientists face is identifying the sample preparation technique that can minimize matrix interferences and maximize target analyte recovery, while maintaining high sample throughput and instrument sensitivity.

Solid phase extraction: High selectivity and sensitivity

The removal of matrix interferences is key to achieving good analytical results. By undertaking efficient and consistent sample preparation before LC/MS or GC/MS analysis, analysts can ensure that their analyte is amenable for analysis. In addition to, minimizing matrix effects, and optimizing instrument performance.

When high selectivity and sensitivity are required, solid phase extraction (SPE) removes the widest range of matrix interferences for cleaner samples. SPE is very specific to match the sorbent and wash/elution conditions to the sample, to extract the target analytes while leaving little or no matrix behind. Many agree that SPE provides the best balance of biological sample cleanliness, accuracy of results, and cost-per-sample.

Watch these educational videos from Agilent to learn:

  • Insights into SPE method development
  • How to optimize an already-existing SPE method using mass balance
  • How to develop a new SPE method with 10-bottle optimization

Maintain control, eliminate variables

“Reliability is a key parameter in developing rugged, high-throughput sample preparation methods. Agilent Bond Elut Plexa SPE products combine innovative research, state-of-the-art manufacturing, and stringent quality-control monitoring, to deliver consistently fast flow rates and reproducible results. Bond Elut Plexa SPE minimizes variability and unknowns inherent to biological samples.

Bond Elut Plexa offers simple, easy-to-use methods with general-purpose extraction mechanisms to simplify SPE. In addition, Plexa provides performance enhancements due to a unique polymeric architecture with a , hydroxylated, amide-free surface, and a nonpolar PS-DVB core. Binding of proteins and lipids on the polymer surface is minimized, resulting in cleaner samples and reduced ion suppression for MS applications. Plexa is therefore ideal for high throughput assays requiring validated performance with minimal method development.

With Agilent Bond Elut Plexa SPE products, you can count on:

  • Faster flow rates: Uniform particles with a narrow size distribution ensure optimal flow characteristics for sample addition and elution during solid-phase extraction.
  • Excellent cartridge-to-cartridge reproducibility: Plexa sorbent particles are manufactured using proprietary polymerization techniques to eliminate fines and achieve a narrow particle size distribution.
  • Less wasted time and sample: The absence of sorbent fines significantly reduces cartridge clogging, which is critical in high-throughput laboratories, and automated applications where SPE must be performed unattended and overnight.
  • More reliable data: Proprietary automated fritting and real time QC processes minimize channels (or voids) in the packed sorbent bed, preventing analyte breakthrough and variable recoveries.

To find out how you can achieve less variability, with more consistent outcomes, in your biological sample analysis, click here and download your free SPE methodology tool kit. This kit features a new SPE poster that provides guidance on sorbents, SPE protocols, and troubleshooting tips.

For Research Use Only. Not for use in diagnostic procedures.