Let me start with a story from many years ago when I was a young customer of ion chromatography. One day, I was introduced to reagent-free ion chromatography (RFIC), where the eluent is generated electrolytically by adding just deionized water. My initial impression was, “How difficult is it to make eluent?” That was until I encountered carbohydrate analysis. Not only did I have poor reproducibility, but I also had no inert gas to keep my hydroxide clean from atmospheric carbon dioxide. I learned more things about hydroxide and manual eluent preparation with that project, too!
After years of using eluent generation (EG), I recognized the value of reproducible data day-to-day, person-to-person and lab-to-lab with a simple method transfer. I can honestly say I would not want to go back to manually preparing eluent unless I had to. I then came across the use of sodium acetate and how its quality can cause issues with oligosaccharide analysis. I have now discovered dual eluent generation (Dual EG) where I can use potassium hydroxide and methanesulfonic acid cartridges instead of using manually-prepared hydroxide-acetate gradient, giving similar results without the variability observed with the quality of acetate. With Dual EGC I can separate a wider range of carbohydrates from monosaccharides to oligosaccharides, all in one run. With Chromeleon Autodilution (with options to do partial loop or vial-to-vial) there is no further dilution as it is all automated. With RFIC just-add-water means less pump maintenance as it only ever sees water. Dual EGC increases instrument up-time leading to improved productivity and automation over a wide range of possible carbohydrate analysis applications. Dual EGC allows for automation not just for simple food and beverage nutritional labeling but also for profiling to check on authenticity of food ingredients.
The definition of authenticity is genuine or having an origin supported by unquestionable evidence. How often have we bought something and thought it was the real thing and discovered later it is not? The more authentic, the higher the price we pay, but how do we know? The price is usually associated with quality. Take agave syrup, for example, which has gained popularity recently as an alternate sweetener. With manually-prepared eluents, high-performance anion-exchange chromatography with pulsed amperometric detection (HPAE-PAD) can be used for carbohydrate profiling after the enzymatic hydrolysis and detect any adulteration (application note 73132). Dual EG can also be used to achieve similar results but with less effort (application note 73896). So, is Dual EG better than single EG? Well, carbohydrate analysis is definitely sweeter with such a wide range that can be covered in one single injection! With the choice of CarboPac column formats, we use standard bore to capillary. With Dual EG, the eluent flow rate is much lower therefore less waste. More data, more results, more samples analysed with one system, and Dual EG. Relax and still be more productive!