Inspection assay

To obtain the necessary information, two different analytical schemes are commonly used. These are (1) an inspection assay and (2) a comprehensive assay. 

Inspection assays usually involve determination of several key bulk properties of petroleum (e.g., API gravity, sulfur content, pour point, and distillation range) as a means of determining whether major changes in characteristics have occurred since the last comprehensive assay was performed. 

For example, a more detailed inspection assay might consist of the following tests API gravity (or density or relative density), sulfur content, pour point, viscosity, salt content, water and sediment content, trace metals... 

On the other hand, the comprehensive (or full) assay is more complex (as well as time-consuming and costly) and is usually only performed only when a new field comes on stream, or when the inspection assay indicates that significant changes in the composition of the crude oil have occurred. Except for these circumstances, a comprehensive assay of a particular crude oil stream may not (unfortunately) be updated for several years. 

In addition to the whole crude oil tests performed as part of the inspection assay, a comprehensive or full assay requires that the crude be fractionally distilled and the fractions characterized by the relevant tests. Fractionation of the crude oil begins with a true boiling point (TBP) distillation using a fractionating column with an efficiency of 14-18 theoretical plates and operated at a reflux ratio of 5 1 (ASTM D-2892). The TBP distillation may be used for all fractions up to a maximum cut point of about 350°C atmospheric equivalent temperature (AET), but a low residence time in the still (or reduced pressure) is needed to minimize cracking. 

The inspection assay tests discussed above are not exhaustive but are the ones most commonly used and provide data on the impurities present as well as a general idea of the products that may be recoverable. Other properties that are determined on an as-needed basis include, but are not limited to, the following (1) vapor pressure (Reid method) (ASTM D-323, IP 69, IP 402), (2) total add number (ASTM D-664, IP 177), and chloride content (ASTM D-4929, IP 244). 

To obtain the desired information, two different analytical schemes are commonly used, namely, an inspection assay and a comprehensive assay. Inspection assays usually involve determination of a few key whole crude oil properties such as API gravity, sulfur content, and pour point—principally as a means of determining if major changes in a crude oil stream s characteristics have occurred since the last comprehensive assay was performed. Additional analyses may be performed to help ensure that the cargo or shipment received is that which is expected to ascertain the quantity of impurities such as salt, sediment, and water and to provide other critical refinery-specific information. Inspection assays are routinely performed on all shipments received at a refinery. The comprehensive assay, on the other hand, is complex, costly, and time-consuming and is normally performed only when a new field comes on stream, or when the inspection assay indicates that significant changes in the stream s composition have occurred. Except for these circumstances, a comprehensive assay of a particular crude oil stream may not be updated for several years. 

An assay varies in depth and complexity depending upon the crude oil type and its final use. The assay can be an inspection assay or comprehensive assay. There are various types of assays, which vary considerably in the amount of determined experimental information ... 

It is shown, that for assay of substances and prepai ations the different approaches ( Confirming and Inspecting ) should be applied. The criteria to analytical procedures uncertainty for tests Uniformity of dosage units and Dissolution ai e developed. 

Priifung, /. test, testing, assay, trial, examination, proof, control, inspection. 

If the true pfCj of the molecule is known, then a simple inspection of the plot of log Pe (or Papp in the case of cellular assays) versus pH can often reveal the values of both log Po and log Pabl-... 

Establishment Inspection Report Establishment License Application enzyme linked immunosorbent assay European Medicines Agency Environmental Protection Agency European Public Assessment Report end of production cell bank erythropoietin... 

Coupled with successful primary prevention are ongoing monitoring programs for the organisms and their toxins, both in the environment and in the seafood. The molluscan shellfish (i.e., oysters, clams, mussels, and scallops) are the species associated with shellfish poisonings. The absence of characteristics such as abnormal taste, smell, or appearance precludes sensory inspection for these toxins. Instead, ensuring seafood safety relies on testing seawater and the seafood itself The assays used to detect toxins in seafood have evolved as analytic methods and instrumentation have improved. The American Public... 

Meldal et al. developed a novel protease assay based on the long-range resonance energy transfer (FRET) [25] fluorescence quenched (EQ) pair 3-nitrotyro-sine/2-aminobenzoic acid. This served to characterize enzyme specificity by direct visual inspection of the resin beads (33). 

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