a new simple and rapid dispersive liquid-liquid microextraction has been applied to preconcentrate tracelevels of zinc as a prior step to its determination by spectrophotometric method. in the proposed method, 4-(2-pyridylazo) resorcinol (par) is used as a chelating agent, and chloroform and ethanol are selected asextraction and dispersive solvent. the optimization strategy is carried out by us...

conclusions in samples stored in plastic syringes, overestimation of pao2 levels should be noted if samples cooled before analysis. in samples stored in plastic syringes, it is not necessary to store samples in iced water when analysis delayed up to one hour. results pao2 of the samples stored at 0°c was increased significantly after 60 minutes (p = 0.007). the paco2 of the samples kept for 30 ...

A new simple and rapid dispersive liquid-liquid microextraction has been applied to preconcentrate tracelevels of zinc as a prior step to its determination by spectrophotometric method. In the proposed method, 4-(2-pyridylazo) resorcinol (PAR) is used as a chelating agent, and chloroform and ethanol are selected asextraction and dispersive solvent. The optimization strategy is carried out by us...

introduction: to cope with novel changes, organizations must think beyond environmental compatibility and seek to take advantage of potential opportunities. a paradigm for this is the enhancement of organizational flexibility, speed, quality, and agility. human resources are the most important tool for enhancement of organizational agility and the most valuable asset of each organization and co...