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.
Piedras Negras is located 441 km north of Saltillo via Federal Highway 57 in the State of Coahuila, Mexico. Piedras Negras is called La Puerta de Mexico (Mexico's Door) because of the flow of commercial traffic and people that passes through it. It is the sister city, across the Rio Grande, of Eagle Pass, Texas. Piedras Negras is well-known for its ranches where sportsmen can hunt species of high-class.