In September 2009, ESA Inc was acquired by Dionex Corp, which has itself been acquired by Thermo-Fisher. ESA Inc, is now a subsidiary of Thermo Fisher Diagnostics. Originally called Environmental Sciences Associates, Inc., now known as ESA, the firm developed a technique to measure lead - an instrument based on an electrochemical technique called anodic stripping voltammetry, or ASV, the first practical method to screen children for blood lead poisoning. The firm shifted focus to researching the neurochemical damage caused by lead poisoning. The firm developed a flow-through electrochemical cell, made out of porous graphite as an alternative to using HPLC with electrochemical detection - the only type of detectors then available used thin-layer or flow across electrodes. This cell design proved to be more stable, selective and generally more sensitive than the thin-layer cells. To utilize the new EC cell, ESA developed the Coulochem® Detector and later complemented this with a complete line of HPLC equipment optimized for EC detection. ESA continued research into areas such as Huntington's, Parkinson's and Alzheimer's Disease. Addressing the disagreement in the neurochemistry community on the level of serotonin (a neurotransmitter) in various areas of the brain, the principal of the firm postulated that what researchers were calling serotonin was actually more than one compound. To investigate this assumption, he assembled four Coulochem detectors and eight chart recorders, and began running samples through eight flow-through electrodes set at increasingly higher potentials. With this array of electrodes he discovered there was a compound co-eluting with serotonin which he was now able to resolve. This new instrument eventually became the current Model 5600 CoulArray® Detector which has moved from being primarily a neurochemical analyzer into virtually almost every type of scientific laboratory, from the food and beverage to the clinical and pharmaceutical industrie
