Automated mass spectrometer/analysis system: A concept

System performs rapid multiple analyses of entire compound classes or individual compounds on small amounts of sample and reagent. Method will allow screening of large populations for metabolic disorders and establishment of effective-but-safe levels of therapeutic drugs in body fluids and tissues

Automated mass spectrometer analysis system

An automated mass spectrometer analysis system is disclosed, in which samples are automatically processed in a sample processor and converted into volatilizable samples, or their characteristic volatilizable derivatives. Each volatizable sample is sequentially volatilized and analyzed in a double focusing mass spectrometer, whose output is in the form of separate ion beams all of which are simultaneously focused in a focal plane. Each ion beam is indicative of a different sample component or different fragments of one or more sample components and the beam intensity is related to the relative abundance of the sample component. The system includes an electro-optical ion detector which automatically and simultaneously converts the ion beams, first into electron beams which in turn produce a related image which is transferred to the target of a vidicon unit. The latter converts the images into electrical signals which are supplied to a data processor, whose output is a list of the components of the analyzed sample and their abundances. The system is under the control of a master control unit, which in addition to monitoring and controlling various power sources, controls the automatic operation of the system under expected and some unexpected conditions and further protects various critical parts of the system from damage due to particularly abnormal conditions

Episodic rainfall influences the distribution and abundance of the regular sea urchin Lytechinus variegatus in Saint Andrew Bay, northern Gulf of Mexico

The distribution and abundance of Lytechinus variegatus (Lamarck) were determined at three shallow-water stations in Saint Andrew Bay, FL, in the northern Gulf of Mexico. Populations were monitored at 4-mo intervals from Aug. 1997 to Aug. 1999 along 2- X 10-m transects, with four transects at each station. In Aug. 1997 individuals ranged in size from 15- to 63-mm diameter (mean = 38 mm; density= 1.4 individuals (ind.) m-2) at Station 1 (Stations 2 and 3 were not sampled on that date). By Oct. 1997 individuals at Station 1 ranged in size from 26 to 62 mm (mean = 48 mm; density = 0.6 ind. m-2), suggesting the growth of individuals within the population. At Station 2, individuals ranged between 50 and 70 mm (mean = 59 mm; densities = 1.0 ind. m-2) and at Station 3 between 30 and 79 mm (mean= 51 mm; densities = 1.4 ind, m-2) in Oct. 1997, indicating a population with no recent recruits. A mass mortality event was observed in April 1998 and was attributed to reduced salinities resulting from above-average rainfall in the previous month. Sea urchins were absent at Stations 1 and 2, whereas at Station 3 postdisturbance recruits were smaller (mean = 28 mm) and densities lower. Sea urchin tests were also observed at beach stations proximate to Stations 1 and 2. By July 1998 the populations had partially recovered at Stations 2 and 3 (densities = 0.6 and 1.1 ind. m-2, respectively), but test diameters were small at both stations. Test diameters had increased in Dec. 1998 at Station 3 when compared with those of July, but individuals at Station 2 showed overall smaller test diameters (mean = 28 mm), and densities had decreased again, presumably after another mass mortality caused by another major rainfall in Sep. In April 1999 test diameters had decreased further at Stations 2 and 3, indicating emigration or death of larger animals. We suggest that the shallow-water Saint Andrew Bay population of L. variegatus is reduced for several years at a time by episodic heavy rainfalls. This observation emphasizes the importance of density-independent processes controlling the distribution and abundance of marine organisms