Ion chromatography (IC) systems are able to separate, detect, and quantify much more than simple ions. High pH eluents can disassociate organic acids, sugars, and carbohydrates, allowing them to be separated on anion- and cation-exchange columns and detected with suppressed conductivity. Ion-exclusion columns allow separation of alcohols, glycols, and organic acids. Pulsed amperometric detection and UV absorbance facilitate detection of a wide range of amino acids, carbohydrates, and alcohols.

The chromatograms featured on these pages show the range of beverage applications available using Dionex IC technology.

Fast Analysis of Phosphate and Citrate in Cola Soft Drinks

Regular cola and diet cola soft drinks usually have a controlled amount of phosphate from added phosphoric acid. Production environments require fast and accurate phosphate analysis to ensure reliable and timely quality control. Reagent-Free^™ IC (RFIC^™) systems, using the Fast Anion IIIA column, allow phosphate analysis to be performed within 4 minutes. Many cola soft drinks, such as diet colas, also contain citrate. As we can see from Chromatogram B, citrate elutes after phosphate. It is important that the citrate peak also elutes quickly, so that the phosphate measurement can also be made in a timely fashion, such that the analysis time does not exceed 4.5 minutes. If this analysis were attempted using the traditional carbonate eluent systems, samples containing citrate could not be analyzed quickly, because the citrate would not be eluted efficiently.

Cations in Diet Cola

Alkaline and alkaline earth cations plus ammonia can be quickly and easily be determined in soft drink beverages using a cation-exchange column and suppressed conductivity detection.

Organic Acids and Inorganic Anions in Apple Juice

This chromatogram shows the dominant anion in apple juice to be malate, which gives the apple its flavor. Quinate, which is a minor but significant peak in this chromatogram, provides the characteristic flavor of cranberry juice.

Organic Acids Using ICE-AS6 in Fruit Juices

Ion-exclusion chromatography (ICE), a form of ion analysis, can be used to determine organic acids in fruit and vegetable drinks. This makes it easy to perform quality control analysis of these products by monitoring specific organic acids that are typical of a given product or sample. Using this separation method, inorganic anions, such as chloride and sulfate, elute in the void volume and do not interfere with the determination of organic acids.

Organic Acids in Cranberry Juice (QC)

This chromatogram illustrates how rapidly organic acids can be measured and quantified by ion-exclusion chromatography, even in difficult sample matrices such as cranberry juice. Peak 1 in the sample chromatogram is the result of highly ionized anions, such as chloride and sulfate, eluting as a group. Weakly ionized organic acids are separated by the ion-exclusion process in approximately 10 minutes.

Trace Organic Acids in Grape Juice Using Suppressed Conductivity Detection

A wide range of rganic acids in fruit juices can be rapidly and accurately determined using ion-exclusion chromatography.

Carbohydrates in Apple Juice

The CarboPac^® MA1 column and a sodium hydroxide eluent can be used to determine major carbohydrates in fruit juices like apple juice. In such a high pH eluent, carbohydrates are anions and are easily separated on an anion-exchange column. Pulsed amperometry can sensitively and selectively detect a wide range of carbohydrates.

Anions in Beer

Ion chromatography is used routinely to analyze the progress of organic acid formation during the brewing process. Using a sodium hydroxide/methanol gradient and suppressed conductivity detection, this anion exchange separation delivers common anions and organic acids in a beer sample. Being able to rapidly quantify these components allows for reliable quality control of the finished product.

Alcohols and Glycols in Beer

Alcohols and glycols are metabolic byproducts of fermentation, and monitoring them helps brewers determine the progress of fermentation, and the quality of the finished product. Ion-exclusion chormatography with pulsed amperometric detection allows rapid determination of ethanol and glycerol in fermentation broths after only simple dilution and filtration of the sample.

Organic Acids and Inorganic Acids in Red Wine

The IonPac AS11-HC column provides a detailed analysis of the organic acids and inorganic anions in a wine sample, using a hydroxide gradient.

Organic Acids in Wines

Organic acids can be determined in wines, without interference from inorganic anions, using ion-exclusion chromatography (ICE).

Organic Acids in Coffee

Using ion-exclusion separation, inorganic anions elute early in the chromatogram. This allows accurate quantification of organic acids, even in difficult matrices, without inorganic ion interference.

Oxyhalides and Bromide in Bottled Drinking Water

This slide documents the accurate recovery of bromide, bromate, chlorite, and chlorate spiked into a bottled drinking water sample. The three oxyhalides are common by-products of disinfection processes, and known to be carcinogens. It should be noted that the original concentration of bromate was 9.2 ppb, which is very close to the U.S. FDA regulation limit of 10 ppb in bottled drinking water, and well above the 3 ppb limit set by the European Union.