In this series, Dr. Kalumbu Malekani, Chief Scientific Officer, Environmental Risk Sciences, explores trends and salient topics in environmental and regulatory science. This month, we hear from Sidney Bluemink, Study Director, Chemistry, Harrogate, UK, about his latest webinar and new QuEChERS article, and his thoughts about future developments in the field of chemistry. 

Kalumbu Malekani (KM): Sid, you presented a webinar in September as part of the AGRO Lunch & Learn series, titled “Navigating Sample Complexity in Residue Analysis”. What is the most important takeaway viewers might get from the webinar?

Sidney Bluemink (SB): The important takeaway is that there are a variety of techniques, methods, and instrumentation options in a residue chemist's toolkit that matches the diversity of challenges presented by residue analytes and matrices. My hope is that the webinar helps to educate and inspire current and future analytical chemists. The webinar indirectly shows there are many facets to the field and that it is potentially challenging, but I enjoy the challenge and I hope it can attract those that also relish this, too.

KM: You recently authored a QuEChERS Methodology Analysis for clients that discusses pros and cons of the application. Why did you feel this was an important topic to write about?

SB:  As my article points out, QuEChERS methodology is not always the first go-to methodology in a research setting, as the main benefit is higher sample throughput which is a big advantage in environmental monitoring. That higher throughput sometimes requires compromises in selectivity that may be needed in research.

In residue chemistry, there will often be large scale, high sample throughput research/risk assessment studies where the use of QuEChERS can bring those economic benefits, but their use is still intermittent because of the potential complexity of integrating a QuEChERS method with an extraction intensive metabolism method, for example.

I feel it was an important topic to cover as it demonstrates there are several applications for QuEChERS methodologies and available variants in a research/risk assessment setting that provide innovative clean up approaches for various matrix and study types. I hope this article can help toward changing mindsets. 

KM: What are the biggest changes you expect in the field of residue chemistry in the next five years?

SB: It is difficult to predict the direction of the field going forward and much of it is dependent on regulatory shifts. For example, decisions on study sets that appropriately qualify the environmental effects of the ever-increasing use of biologics for plant protection, or therapeutic (or biopharmaceutical) medicines. In particular, I mean biological response modifiers that affect immune response in humans and are large extremely complex protein-based molecules with molar masses in the thousands.

Traditionally, residue chemistry has mostly been concerned with relatively small synthetic molecules such as pesticides, biocides, and pharmaceuticals.  With a shifting regulatory landscape involving biologics, macromolecules and polymers, traditional residue chemistry laboratories will need to adapt their training, skillset, and instrumentation according to more macromolecule-facing techniques. 

In terms of technology, I can see more residue studies employing high-resolution mass spectrometers. Traditionally these instruments have been more established in qualitative rather than quantitative analytical chemistry as a result of the traditional expense of this technology and the perception that they lack the robustness of triple-quad mass currently ubiquitous within residue-based studies. This is changing and I can see this trend continuing. 

Another change I can see happening is greater adoption of gas chromatography with atmospheric pressure chemical ionization (GC-APCI). Traditional GC/MS predominantly uses helium as a carrier gas. Helium is a finite resource tied to natural gas production and its use is becoming increasingly cost prohibitive. Hydrogen is a much more cost-effective alternative to helium but it is an imperfect solution due to the expense in upgrading infrastructure to handle the explosive gas and the fact it just cannot deliver the same performance as helium. Nitrogen is the cheapest and safest option but will not work with traditional GC/MS for reasons I will not go into here. For GC-APCI however, nitrogen (or any other traditional carrier gas for that matter) can be used as the carrier gas whilst delivering at least equivalent performance. For this cost and supply reason alone, I can see laboratories increasingly adopting this technology over the coming years.

KM: Thank you for sharing your insights with us. We look forward to learning more from you in future webinars and publications. 

Contact us to speak with our experts or meet with members of our team at the upcoming SETAC Europe Annual Meeting in Seville, Spain, at stand 211.