Bond instrument continued

Besides the continuous improvements of FTIR-VCD instruments described above, some exciting new developments related to VCD measurements have been reported in recent years. These include the developments of matrix isolation FTIR-VCD instruments and of laser based real time VCD spectrometers. These new developments are associated with brand new applications and research directions, such as combining the matrix isolation technique with VCD spectroscopy to probe conformationally flexible chiral molecules and H-bonded chiral molecular complexes, and using femtosecond laser VCD instruments to record time resolved VCD spectra for monitoring fast chemical reactions or folding and unfolding events of peptides and proteins in solution. These will be discussed in more detail in Sects. 4.5 and 4.6. 

There are several commercially available instruments using sorption systems for sample pretreatment. A representative example of those working in a continuous fashion is the Varian AASP (Advanced Automated Sample Processor) [10]. This uses cassettes of ten sorbent cartridges, each of which is packed with 40-50 mg of a particular bonded silica gel. It features three essential differences from typical manual systems, namely the use of lower sample and solvent volumes, the utilization of pressure rather than vacuum and the fact that the liquid emerging from the cartridge is completely eluted to the HPLC system, thereby increasing the sensitivity. Analytical Biochemistry Laboratories (ABC) markets a module (GPC 1002 A) for automated clean-up of residues in extracts by use of a gel-permeation column. 

Combined inspection and testing is also necessary on some equipment because some faults cannot be seen by just looking - for example, the continuity and effectiveness of earth paths on class I equipment. For some portable appliances the earth is essential to the safe use of the equipment and, therefore, all earthed equipment and most extension leads should be periodically tested and inspected for these faults. All portable appliance test instruments (PAT Testers) will carry out two important tests earth bonding and insulation resistance. 

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