Sodium thiosulfate is approved for the treatment of acute cyanide poisoning. An ion chromatography (IC) method has been proposed to replace existing titration-based assays in the Sodium Thiosulfate and its Injection monographs. Another IC method has also been proposed for determining impurities. This application note evaluates both methods following the USP guidelines (<1225>, Validation of Compendial Methods). A Dionex ICS-5000+ IC system with a Dionex IonPac AS12A column and suppressed conductivity detection were used for both method evaluations. An ICS-6000 can be used for this application.
This application note demonstrates a simple combustion ion chromatography (CIC) method to determine fluoride in tea. Using the CIC system including a Mitsubishi Automatic Combustion Unit AQF-2100H system and a Thermo Scientific Dionex Integrion HPIC system, fluoride in tea is determined in 20 min (11 min if the combustion and chromatography functions are overlapped), a significant time savings over the current Chinese national method which requires more than a hour. The CIC method is sensitive (MDL=1 ppm), precise, and accurate. The only sample preparation required is to grind and dry the tea.
When coal is burned, the exhaust contains halogens that can be released into the atmosphere as acid gases such as hydrogen chloride (HCl) and hydrogen fluoride (HF), which can harm vegetation, animals, and infrastructure directly or cause acid rain. In this application note, coal samples were combusted in the Mitsubishi AQF-2100H system and then fluorine and chlorine were accurately and precisely determined using the Dionex ICS-2100 Ion Chromatography System with a Dionex IonPac AS15 anion-exchange column set.
Sour gas is treated with amine and recycled amine (scrubbing) solutions to absorb toxic and undesirable H2S and CO2 create sweet natural gas. Salts of organic acids and sulfur species, heat stable amine salts (HSAS) can concentrate over time. Analysis of these HSAS are needed to assess the efficiency of scrubbing solution and can be quite challenging. In this technical note, HSAS in methyldiethanolamine (MDEA) were separated with high efficiency on a 2 mm i.d. IonPac AS11HC-4μm column using a high pressure ion chromatography system.
In the food and beverage industries, sulfing agents have been used as preservatives to prevent microbial spoiling and browning reactions in a wide variety of food and beverage products. The U.S. Food and Drug Administration (FDA) requires labiling of any food or beverage containing a sulfite concentration > 10 ppm. This application describes an imporved ion-exclusion chromatography with pulsed amperometric detection method for the determination of total and free sulfite in foods and beverages.
