Pretreatment continued glass

The reliability of the metal/polymer bond under moist thermal cycling, moist and dry thermal environments, and simulated soldering conditions was examined. Similar data for 30 % glass-filled polyetherimide have been presented previously Table X displays the cycling and thermal data. As can be seen in the table, the metal/polymer bond was extremely durable. Simulated soldering experiments were conducted on polyetherimide film pretreated with nitric acid as the impregnator. liiis material has a glass-transition temperature of 216 C and a continuous use temperature of ISS C. 

Preparations, conducted at 40°C, take place in a stirred glass vessel equipped with sensors (pH, temperature, torque motor measurement of the stirrer shaft) allowing the control of the diffrrent steps of the preparation. Reactants pretreated at Ae preparation temperature, are introduced in the reactor at defined mass flow rates by means of calibrated peristaltic pumps. Reactants can be introduced in the reactor, successively (batch process) or simultaneously (semi-continuous process). In the later case reactants are mixed in the feeding pipe. 

Workstations and robotic systems are very expensive, so inexpensive alternatives such as flow configurations have been developed for automated sample preparation. The earliest flow systems for sample preparation were used for GC determination (with flame ionization detector [FID] or electron capture detector [EGD] detection) of organic compounds, which requires no special extraction or derivatization, in environmental matrices [30-34]. Automated GC-MS systems for the determination of volatiles in water or air [35-38] are the most commonly reported. Detailed descriptions of these systems can be found elsewhere in this book. Few continuous flow systems (CFSs) for the automated pretreatment of biological fluids in combination with GC-MS have been developed to date. The intrinsically discrete nature of the GC-MS sample introduction mechanism makes online coupling to continuous flow systems theoretically incompatible for reasons such as the different types of fluids used (liquid and gas) and the fact that the chromatographic column affords volumes of only 1 to 2 j,l of cleaned-up extract. Therefore, the organic extracts from CFSs have traditionally been collected in glass vials and aliquots for manual transfer to the GC-MS instrument (off-line approach) only in a few cases is an appropriate interface used to link the CFS to the GC-MS instrument (on-line approach). These are the topics dealt with below. 

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