Electron capture detector (ECD). Electron capture detectors (ECD) are typically used in environmental testing for detecting PCBâs, organochlorine pesticides, herbicides and various halogenated hydrocarbons. With an electron capture detector, a beta emitter such as radioactive tritium or 63Ni is used to ionize the carrier gas.
Las Piedras: Las Piedras, city, southern Uruguay. It is situated in a wine-growing district just north of Montevideo. It was the site of a decisive battle (1811) in Uruguayâs struggle for independence, in which the revolutionaries defeated Spanish forces. Las Piedras is among the largest cities in Uruguay. It is known for its ostrich farming and horse racing. Las Piedras is on the main highway and railroad linking Montevideo with TacuarembÃ³ and Rivera. Pop.
The Piedra River begins near the Continental Divide in. the Weminuche Wilderness. It's a forty mile long stream. that's a tributary of the San Juan River but where it once. joined the San Juan is now under water in the Navajo. Reservoir. The Piedra River is formed by the. confluence of its East and Middle Forks, both of which. begin in the San Juan National Forest. The Middle Fork. of the Piedra River, the larger of the two, flows for about.