PPG, calibrant

Hie ions chosen for the optimization should be in the middle of the cahbration range or in a specific region of interest (e.g., m/z = 195 of caffeine or m/z = 906.7 of PPG calibration solution). Before using the automatic tuning procedure to demonstrate diat die transmission of ions into die MS is optimum, die ESI source sprayer should be manually adjusted to establish a stable spray of ions into die MS and to ensure diat enough ions are detected to calibrate die MS. 

Figure 2. Intrinsic viscosity-molecular weight data for polystyrene and polyvinyl chloride measured by osmometry and by SEC using broad MWD standard calibration (polystyrene (m) M = 7,06 X 10 in THF/1% PPG (O) [ ] =...

Figure 13.11. Calibration in ESI positive mode using PPG. (Courtesy of Sciex API3000.)...

Mass Calibration The process by which the mass analyzer is calibrated such that a measured and displayed m/z is accurate. Well-characterized calibration compounds are utilized, and measured m/z values for these compounds are compared to theoretical m/z values. Calibrants commonly used include various polymeric species (such as polypropylene glyol, or PPGs poly tyrosine (poly-t)) or fluorinated species (perfluorokerosene or PFK) but can be any compound or mixture (Nal/KI) of compounds properly characterized for MS. 

Readily available proteins have been suggested as reference compounds as well. A mixture of the peptide MRFA and myoglobin has been nsed for calibration by Thermo Finnigan. The use of a protein solntion rather than Csl/Nal or PPG as a reference compound is sometimes reconunended for protein analysis, because the multiple-charge ions of proteins may behave differently from single-charge cluster ions [28]. 

Drilling experience has shown that this technology can predict pressures to within 0.75 ppg at target depths, provided the low-frequency trends of seismic interval velocities are of good quality and are within 5-10% of well velocities. This has been observed by numerous case studies and applications within BP s exploration and exploitation community. The current technique predicts effective stress quantitatively and directly, unlike any other method. The method is completely pre-drill in nature it does not use trend data and it is not tied to block-to-block well calibration. However, it does require an understanding of the local geology and in particular, of rock properties. In addition, the reliability of the predicted effective stress and pore pressure is limited by the resolution of the seismic velocity. 

With the exception of the Observer Differences, all of these conditions can and should be controlled. If the light booth or the surround need to be painted, the paint formula is as follows PPG 80-110 Interior Latex Flat, B-46, L-2Y, 0-12. This will make one gallon of paint. Cleaning and maintenance of the reflectors and filters will keep the colors more vivid between scheduled calibration. 

The calibration of size exclusion chromatography measurements for the determination of the molecular weights of oligolactone macromonomers was carried out using PPG and PS as standards. Results are compared with those obtained by end-group analysis with proton NMR14 refs. 

---