Recently introduced and Pittcon 2011 gold-awarded LECO's Folded Flight Path™ (FFP™) TOFMS technology enables mass resolution of 100,000 FWHM, mass accuracy <1 ppm, and acquisition rates of up to 200 spectra/second—all with fine isotopic abundance measurements to facilitate high-confidence analyte identification. Applications from the field of pesticides and other food contaminants analysis will be shown in this presentation.

Over a dozen states in the USA have legalized medical marijuana. Therapeutic benefits include pain relief, control of nausea and vomiting, stimulating appetite, and muscle relaxation. Unfortunately, patients still have no assurances on the safety of the medicine due to potential harmful levels of pesticide residues, and currently, no methods for analysis of these residues in marijuana exist. We used the Quick-Easy-Cheap-Effective-Rugged-Safe (QuEChERS) extraction approach for pesticides in marijuana.

The resulting complex extract required cartridge solid phase extraction cleanup, followed by comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GCxGC-TOFMS). Good recoveries were obtained for the developed method for most pesticides (over 90 were examined), and incurred pesticide residues were detected in some of the illicit marijuana samples used for the work.

Accurate qualitative and quantitative analysis of perfumed or flavoured products is essential to the flavour and fragrance industry. Especially when unknown samples need to be analyzed, traditional methods of GC analysis often lead to only vague results and often require time consuming and cumbersome sample preparation techniques such as solvent extraction (liquid/liquid, Soxhlet, Likens-Nickerson). The technique of dynamic headspace requires minimal sample preparation and significantly reduces overall analysis time while also improving data quality. In this work, the dynamic headspace technique is applied to different types of consumer products. The analysis of neat perfume oil is compared with that of consumer products containing the same oil.

Persistent organic pollutants (POPs) are a group of chemicals that includes halogenated pesticides, brominated diphenyl ethers (BDEs) and polychlorinated biphenyls (PCBs). Due to the lipophilic nature of these components, they accumulate in the fatty tissue of animals and bioaccumulate up the food chain. According to the World Health Organization, human breast milk is an ideal matrix to monitor the levels of POPs in not only the mother and infant, but also as a key indicator of the levels of these chemicals in the local environment. Current methodology for the analysis of halogenated pesticides, PCBs, and BDEs can be expensive, solvent intensive, and time-consuming. The QuEChERS extraction approach coupled with a silica cartridge SPE cleanup may be an attractive sample preparation alternative for biomonitoring efforts for halogenated POPs in milk. Comprehensive two-dimensional gas chromatography (GCxGC) with an electron capture detector (ECD) may also offer a more cost-effective alternative. Method development was done using whole cow milk and later compared to a NIST Standard Reference Material of Human Breast Milk.

Polyaromatic hydrocarbon analyses are performed regularly throughout the world for both food safety and environmental testing. Many organizations test for PAH residues in food products, but the analyte lists vary between organizations and countries. For example, in the United States, the EPA, FDA, AOAC, and NOAA all test for PAHs, but they do not share the same target compound lists. Internationally, the EU and individual countries test for different PAH compounds. Chromatographic methods are typically tailored to specific target compounds and are not transferable when target compounds change. A further complication is the need to separate interfering compounds, like triphenylene, perylene, and benzo[e]pyrene, that are not considered target compounds but that do occur in samples.

In this work, we developed chromatographic solutions that allow the separation of 29 PAH compounds, including interfering compounds, by both GC and HPLC. Chromatographic resolution of PAH compounds from EPA and EU lists, including isobaric compounds and known interfering compounds, was achieved on the Rxi®-17Sil MS column. HPLC separation was accomplished by combining two HPLC columns in series; a PAH-specific phase and an aromatic bond selective phase. Separate column selectivities were tested and then combined based on a predicted ratio of the column lengths that would result in no coelutions. Temperature was also determined to play a critical role in the elution order and resolution of the PAHs tested. Time programmed fluorescence detection was optimized to yield the best sensitivity possible—ppb range—with closely eluting compounds.

Developing countries like South Africa have the same needs as any country with regards to pesticide residue analysis for food. First, they want to protect internal consumer health. And second, if they are to export their food, they must be able to prove that pesticides do not exist above maximum residue levels required by the import country. To accomplish these goals, they need fast, simple, repeatable, accurate, multi-residue sample preparation and analysis methods. QuEChERS, as a sample preparation technique, is very well suited to this task.

We did "hands on" QuEChERS workshops as part of a training effort across South Africa at the University of Pretoria, the University of KwaZulu-Natal (Pietermaritzburg and Westville campuses), the Forensic Chemistry Laboratory in Cape Town, and the National Metrology Institute of South Africa. To match the fast sample preparation afforded by QuEChERS, we developed a fast 9.7 min. GC-TOFMS analysis so the students could analyze their samples, then quantify and review the results before the half-day course ended. Students analyzed fruits and vegetables, wine, blood, spices, seafood, and other samples.

Medical marijuana, long recognized for therapeutic benefits like pain relief, nausea and vomiting control, appetite stimulation, and muscle relaxation, is currently legal in over a dozen US states. Unlike other prescription drugs, which are regulated by the US Food and Drug Administration, medical cannabis is still considered a Schedule 1 drug and is illegal according to US federal laws. Consequently, patients have no assurances on the safety of their medicine due to the potential for harmful levels of pesticide residues.

The Quick-Easy-Cheap-Effective-Rugged-Safe (QuEChERS) extraction approach was applied to marijuana. The complexity of the sample required cartridge solid phase extraction cleanup and comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry (GCxGC-TOFMS) for pesticide residue analysis. In addition, the sample extracts were diluted and analyzed by liquid chromatography-tandem mass spectrometry (LC/MS/MS) for comparison and for determination of pesticides such as bifenazate and abamectin that are not amenable to gas chromatography.

Currently, the United States Department of Agriculture (USDA) regulates only infestation and disease on imported cut flowers, representing approximately 70% of the rose market. This regulatory situation unintentionally encourages heavy use of pesticides, which are not regulated by USDA for cut flowers. Heavy pesticide use can have serious consequences for the health of workers in the flower industry and their local environment. To address those issues, an organic flower industry exists that advertises agricultural sustainability practices, including limited pesticide use.

In this contribution, the Quick-Easy-Cheap-Effective-Rugged-Safe (QuEChERS) sample preparation method was used with GC/MS and GCxGC-TOFMS to analyze pesticides on cut roses. Pesticide classes selected for investigation include organochlorine, organophosphorus, carbamate, pyrethroid, and triazole compounds that are routinely used by the flower industry. Development and optimization of sample preparation, including extraction and cleanup, will be highlighted. Baseline residue levels for organic certified roses and non-certified roses will be estimated in hopes of determining whether "a rose is a rose is a rose."