Sample handling loading

A major advantage of static SIMS over many other analytical methods is that usually no sample preparation is required. A solid sample is loaded directly into the instrument with the condition that it be compatible with an ultrahigh vacuum (10" —10 torr) environment. Other than this, the only constraint is one of sample size, which naturally varies from system to system. Most SIMS instruments can handle samples up to 1-2 inches in diameter. 

A stream of ethylene is fed into the reactor by use of quaternary LC pumps and subsequently dissolved in a 1.90 ml h toluene stream [1]. Ethylene is handled at 60 °C, well above the critical temperature. Catalyst additions are fed via HPLC-type sample injection valves. Various combinations of precatalysts and activators were sampled and loaded by an autoinjector. Catalyst solutions typically were diluted 20-fold within the micro reactor. 

Capacity Another consideration is the capacity of the laboratory to handle the work involved in a given method. For example, a capillary electrophoresis method would not be chosen if the laboratory does not have the instrument. It is also important to look at such factors as other equipment needed, the supplies needed, etc., or whether the laboratory can follow the required health and safety regulations, etc. Sometimes there may not be enough manpower or equipment to handle the sample work load. In that case, storage and refrigeration can also be a problem. 

Ethylene is handled at 60 °C, well above the critical temperature [19]. Various combinations of precatalysts and activators were sampled and loaded by an autoinjector. 

Therefore, minimal sample handling is advisable. In order to overcome the problem of limited sample loading, Guzman conceived and demonstrated the concept of on-line preconcentration with CE using a cartridge containing a bed of adsorptive phase (5). In the present work we describe the use of nonspecific on-line preconcentration-CE, on-line immunoaffinity-CE (lA-CE) and on-line microreactor enzyme digestion-CE for the analyses of proteins. 

Commercial lateral flow assays are assembled in plastic housings to simplify sample handling and to protect users from the contact with assay components and potentially dangerous samples. Samples are usually mixed with a diluent buffer and loaded onto the strips. After absorption of the sample, strips can be washed with a second chase buffer to decrease background and to increase sensitivity of detection. In a research environment, these tests can be run in 96-well plates with nitrocellulose strips dipped into wells containing samples. 

For similar-sized samples, e.g. fused beads, pressed powder pellets, or metal disks, there are innovative concepts to handle samples without sample holders. Instead of a sample holder catcher, the sample magazine uses a low-vacuum suction device to ensure direct, safe transport and loading, requiring only two sample holders for the internal sample handling (Fig. 6). For laboratory automation concepts, e.g. in the cement industry, the spectrometers can be equipped with a process automation sample magazine to handle samples in steel rings without sample holders and a turning device to take process samples from a conveyor or a robot. 

Sample handling selection of a representative portion, preparation, and loading into the pyrolyzer in a reproducible way. 

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