The U.S. Environmental Protection Agency amended the Code of Federal Regulations (40 CFR Part 136) on March 12 to provide full approval for a new method: "Digestion and Distillation of Total Cyanide in Drinking and Wastewaters using MICRODIST and Determination of Cyanide by Flow Injection Analysis," also referred to as QuikChem Method number 10-204-00-1-X by Lachat Instruments.
This rule modifies the testing procedures approved for analysis and sampling under the Clean Water Act and Safe Drinking Water Act, and applies to all facilities that must conduct monitoring and provide reporting to comply with National Pollutant Discharge Elimination System (NPDES) and National Primary Drinking Water Regulations (NPDWR) permits.
"We're very excited to receive EPA approval for our cyanide methodology," said Greg Hirt, director of sales for Lachat Instruments. "Our customers have always loved the simplicity, performance and safety of the MICRODIST product, and the fact that it can now be used for both NPDES and NPDWR compliance reporting purposes is a significant benefit. When you couple MICRODIST with Lachat's QuickChem 8500 Flow Injection Analysis system, you have one of the most productive, accurate and easy-to-use methodologies for determination of cyanide on the market today."
The MICRODIST system quantitatively scales down the sample and reagent volumes like those required by macro-distillation in EPA methods.
MICRODIST is a batch micro-distillation system that uses sample volumes of less than 10mL. The key benefit of the system is a disposable, or recyclable, polypropylene tube assembly (U.S. Patents 5,022,967 and 5,304,287). MICRODIST allows users to distill up to 21 samples simultaneously for cyanides, sulfide and ammonia in 30 minutes, and phenolics and tritium in 90 minutes. MICRODIST also eliminates the need for bulky, expensive, clumsy and time-consuming glassware-based distillation units while accommodating liquid and solid samples.