Advantages of CAD

CAD (computer-aided design) prototyping uses kinematic and dynamic analytical methods to perform many of the same tests on a model. The inherent advantage of CAD prototyping is that it allows the engineer to fine-tune the design before a physical prototype is created. When the prototype is eventually fabricated, the designer is likely to have better information with which to actually create and test the prototype model. 

Another advantage of CAD is that the quality of delinea on (line Wli t, shape and size of letters and numbers, etc.) is usually much bettear thanthat ne by the hand of the average draftsman. ... 

Task 4 [HI Now listen to the tape and list any advantages of CAD. Combine your answers with others in your group to make as full an answer as possible. When you have iinished. compare your answers with the list you made in Task 2. 

CAM describes a system that can take a CAD product, devise its essential production steps, and electronically communicate this information to manufacturing equipment such as robots. The CAD/CAM system has offered many advantages over past traditional manufacturing systems, including the need for less design effort through the use of CAD and CAD databases, more efficient material use, reduced lead time, greater accuracy, and improved inventory functions. 

Based upon the advantages of the other techniques presented prior to LC-MS, large volume injection HPLC-UV, and HPLC-CAD, the decision to use electrochemical detection would be driven primarily by a unique analytical need, equipment availability and previous experience of the analytical chemist. A complex chemical matrix should not be of concern at most there could be some residual cleaning agent and residual excipients in addition to the active pharmaceutical ingredient. Since the matrix in cleaning verification is typically simple, electrochemical detection would not be the primary detection technique. However, the sensitivity afforded by ECD is excellent and can meet the most stringent of the acceptance limits outlined in Table 15.2. 

A promising alternative to HPLC and TLC is micellar electrokinetic chromatography (MEKC). Pietta et al. (1998a) used a 25 mM tetraborate buffer containing 30 mM sodium dodecyl sulfate (SDS) at pH 8.6 for the separation of CADs. The separation was completed within 20 min with good resolution. The advantage to this method is that the cost of operation is less than HPLC, because organic solvents are not needed. 

The main advantage of MS/MS is its abihty to analyse specific target molecules directly from biological matrices without any sample preparation. One important application of MS/MS in food analysis can be the rapid screening of intact fruits or vegetables for the presence of mycotoxins or pesticides. For example intact lettuce leaves can be introduced directly into the ion source and analysed for the presence of the pesticide parathion. The CAD (methane gas) spectrum of this pesticide shows the parent ion at m/z 291 and two daughter ions at m/z 169 and m/z 154. If the peak at m/z 291 of the normal spectrum of the contaminated lettuce leaf is selected and its CAD spectrum is recorded and... 

The application of MS/MS offers the advantage of simplifying cleanup procedures. To this end, CAD MIKES was applied to the detection of sulfonamide drugs and decomposition spectra were reported from [M + H]+ ions produced under Cl (i-C4H10)119. Equation 45 summarizes the most significant pathways leading to fragment... 

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