Archive for the ‘Sample Cleanup’ Category

Upcoming revisions to three wastewater methods reviewed at NEMC 2017

Monday morning, representatives from the EPA’s wastewater office reviewed the significant changes for the three major GC wastewater methods: 608.3, 624.1, and 625.1. The overarching goals were to modernize the methods and bring the language and QC requirements in line with the methods from the drinking water and hazardous waste offices. The methods have been […]

The Clog Blog

Clogging and over pressuring are definitely problematic for Liquid Chromatography columns. Back in 2005 John Dolan’s sage advice to chromatographers to make an LC column last forever was simple, “Never open the box!” As John pointed out, this is not practical and I have to agree. But as an LC column manufacturer I have seen […]

Material Composition of Resprep® Manifold Replacement Parts

A customer asked me yesterday what material certain items for our SPE manifolds were made from.  The answers are below.     Catalog # 26083 is Nylon Catalog #’s 26130 & 26131 are Polypropylene Catalog # 26084 is PTFE   For those of you who need to avoid sample contact with PTFE, we also sell […]

EPRW: European Pesticides Residue Workshop in Sunny Cyprus

                                    Just wanted to let everyone know that we have published our presentations we presented at EPRW (European Pesticide Residue Workshop) last month in Limassol, Cyprus. It was a great meeting in a beautiful location. It was a pleasure to […]

Extraction Method for Cannabinoid Analysis in Edibles: Too Much of a Good Thing

After a long blog hiatus, I’d like to address one of the most frequently-asked questions we get from cannabis labs: “how do we quantitatively extract cannabinoids from edible matrices?”. With the huge number of matrices out there, limited peer-reviewed data, and lack of sufficiently concentrated reference standards for spiking, it’s no wonder that after several […]

Pesticide analysis for cannabis flower: method and data overview

Pesticides in cannabis has been a hot topic lately and we have been getting many requests for help with this analysis. We did work on pesticide residue testing in cannabis about 6 years ago. At that time, we were limited to testing our methods with a small amount of seized material. Recently, we have been […]

Ernst Bayer Award to Junior Scientist Marco Nestola

The Working Group “Separation Science” as part of the German Chemical Society (GDCh) tenders the Ernst Bayer award for an outstanding publication in the field of analytical separation techniques to young scientists. The 2015 award winner, Marco Nestola, received the prize personally during the 26th PhD-Conference, realized by the WG Separation Science from 10th to […]

7th International Symposium on Recent Advances in Food Analysis (RAFA)

The 7th International Symposium on Recent Advances in Food Analysis, better known in short as RAFA, starts this week in Prague, The Czech Republic.  This is my tenth anniversary for this biennial meeting, where the organizer, Jana Hajšlová, invited me to give the lecture, Using the QuEChERS Sample Preparation Method and GCxGC-TOFMS to Determine Pesticides […]

Difficult QuEChERS extracts: Removing fatty acid interferences

Using the QuEChERS extraction and cleanup method for high fat commodities such as, nuts, dairy, fish, and avocado can be difficult to analyze for pesticide residues.  Using the dispersive solid phase (dSPE) cleanup sometimes is just not enough to adequately remove the fatty acid co-extractives. Check out this technical article on how to quickly yet […]

QuEChERS – Where to start?

Enjoy the tip!* I am often asked for QuEChERS product recommendations. Usually the request is something like, “I need to test pesticides in _____” and that blank can be just about anything…sometimes not even food. Unless it is something I have tested before, I usually take a quick look online to determine the approximate composition […]