It’s 8.45pm. I’m sitting watching England labour against a Slovakia team in the Euro 2016 championship. The half time whistle blows as I watch 22 athletes walk off the pitch, jealous of their incredible physiques and how their daily jobs allow them to stay in tip-top physical condition. I rub my ever expanding stomach as my fiancé brings me my evening meal; a busy day for both of us means it’s take-away food tonight. I rub my belly again lamenting my lack of self-control and wishing I hadn’t eaten so much on my recent trip to southern Spain. “Do you want a drink?” – “Go on then…” she brings me a beer…great. I don’t complain as I sip my very nice local beer (a Father’s Day present I might add). “Right, that’s it! I need to do some exercise.” But when do I get the time? The match is back on in 10 minutes… “Why don’t you go on a diet?” she says. But which one? “ Ann is doing that Aloe Vera diet…” I’ll save you from the rest of the conversation; I’ve never been one to diet – especially the latest one, I’d much rather be out cycling or running.
What should be in my glass?
The diet in question was a type of juice fasting diet where you replace meals with a combination of several litres of Aloe vera juice, protein shakes, Garcinia supplement (a fruit native to Asia) and bee pollen tablets over a nine day period. I can’t comment on the validity of the diet or it’s successfulness, but what did make me think was the volume of Aloe Vera which is consumed; and more specifically how well-regulated these juices are. According to EU legislation (article 20), no specific MRLs (Maximum Residue Levels) are present for juices and as a result the corresponding MRL for the raw agricultural commodity is applied taking into account the relevant processing factors. Other major international bodies also have strict testing criteria – Good news. But how do you go about testing to see if your juice is compliant?
Extracting the Information
QuEChERS is now one of the most widely used extraction techniques for food analysis by both GC and LC methods. Since its inception by Anastassiades et al (Anastassiades et al. JAOAC Int. 86  412-431) many different variations of the QuEChERS methodology have been employed with distinct advantages and disadvantages. One of the main benefits to the QuEChERS extraction is that is easy to perform, uses very little lab equipment and the salts/sorbents required are commercially available in pre-prepared kits making it easier to maximise throughput whilst minimising cost. Coupling this simple technique with a powerfully selective and robust GC-MS/MS analyser can provide a targeted approach to the identification and quantification of GC-amenable pesticide residues in these juices, allowing the legislative requirements to be met and ensuring that if you decide to try this type of diet, you can be safe in the knowledge that your uninspiring liquid lunch isn’t filling you with the very toxins which you are trying to cleanse yourself of.
Like what you are learning?
For more information on recently updated method validation procedures, please refer to the SANTE Analytical Quality Control Guidelines (SANTE/11945/2015) and visit the ThermoFisher pesticides learning centre for further resources on the analysis of pesticides
England ended up drawing the game and I haven’t started a diet; oh well, tomorrow is a new day – perhaps I’ll stretch my legs, or my trousers.