Mass-selective detector

Recently, multidimensional GC has been employed in enantioselective analysis by placing a chiral stationary phase such as a cyclodextrin in the second column. Typically, switching valves are used to heart-cut the appropriate portion of the separation from a non-chiral column into a chiral column. Heil et al. used a dual column system consisting of a non-chiral pre-column (30 m X 0.25 mm X 0.38 p.m, PS-268) and a chiral (30 m X 0.32 mm X 0.64 p.m, heptakis(2,3-di-(9-methyl-6-(9-tert-butyldimethylsilyl)-(3-cyclodextrin) (TBDM-CD) analytical column to separate derivatized urinary organic acids that are indicative of metabolic diseases such as short bowel syndrome, phenylketonuria, tyrosinaemia, and others. They used a FID following the pre-column and an ion trap mass-selective detector following the... 

Chromatographic systems were finally coupled with relatively inexpensive, yet powerful, detection systems with the advent of the quadrupole mass selective detector (MSD). The operational complexity of this type of instrumentation has significantly declined over the last 15 years, thus allowing routine laboratory use. These instruments... 

Gas chromatograph, HP 5890 equipped with an HP 7673A autosampler and an HP 5972 mass-selective detector... 

Hewlett-Packard Model 6890 gas chromatograph with capillary split/splitless inlet with HP5973 mass-selective detector equipped with an autosampler Shimadzu GC17A gas chromatograph with capillary split/splitless inlet with flame thermionic detector equipped with an AOC-17 autoinjector... 

Mass-selective detector, MSD5973, electron ionization energy 70 eV, ion source temperature 135 °C mjz 412 (pyraflufen-ethyl), 398 (E-15), 326 (E-16) and 340 (E-3)... 

Gas chromatograph [Flewlett-Packard (FIP) 5890 or 6890 GC with HP 7673 or 6890 Series injector and OI Analytical Model 5220 electrolytic conductivity detector or 5360 halogen-specific detector HP 5890 or 6890 equipped with HP 7673 or 6890 Series injector and HP 5970 or 5972 mass-selective detector]... 

Specificity is unsurpassed. Traditionally, MS was performed on very large and expensive high-resolution sector instruments operated by experienced specialists. The introduction of low-resolution (1 amu), low-cost, bench-top mass spectrometers in the early 1980s provided analysts with a robust analytical tool with a more universal range of application. Two types of bench-top mass spectrometers have predominated the quadrupole or mass-selective detector (MSD) and the ion-trap detector (ITD). These instruments do not have to be operated by specialists and can be utilized routinely by residue analysts after limited training. The MSD is normally operated in the SIM mode to increase detection sensitivity, whereas the ITD is more suited to operate in the full-scan mode, as little or no increase in sensitivity is gained by using SIM. Both MSDs and ITDs are widely used in many laboratories for pesticide residue analyses, and the preferred choice of instrument can only be made after assessment of the performance for a particular application. 

As a rule, a confirmatory GC measurement is performed with a capillary column of different polarity and/or a different detector. The mass-selective detector (MS) (Module D4) is especially suitable for the confirmation of results. 

Gas chromatograph fitted with a thermionic nitrogen-specific detector Gas chromatograph fitted with a quadrupole mass-selective detector... 

Inject an aliquot of the sample solution into the gas chromatograph. An Agilent 6890 Series gas chromatograph fitted with a 5973 Series mass-selective detector has been found to be suitable for this analysis. 

Gas chromatography/mass spectrometry (GC/MS) Gas chromatograph equipped with a split/splitless injector, autosampler, DB-5 MS fused-silica column, 15 m x 0.25-mm i.d., 0.25-qm film thickness and mass-selective detector... 

Mass-selective detector, MSD5971A Temperature 280 °C Target ion m z 173 Reference ion m z 323 Helium carrier gas, O.bmLmin ... 

Hewlett-Packard 6890 Series gas chromatograph with Model 5973 mass-selective detector DB-1701, 30 mx 0.25-mm i.d., 0.15-mm film thickness (J W Scientific, Cat. No. 1220731)... 

Although the data generated by a MIP emission detector for GC are similar in many ways to those produced by a mass-selective detector, the information provided is often complementary [68]. An AES detector provides ... 

This is used in rubber analysis. HPLC combined with a mass selective detector enables unknown samples to be analysed. 

Chemicals used in this study were obtained from Aldrich Chemical Company. 1H NMR spectra were obtained on a Varian EM-360, 13C NMR spectra were obtained on a JEOL-FX-60Q or a GE QE-300. An Analect FX-6200 FT-IR spectrometer was used for infrared spectroscopy and a Hewlett-Packard Model 5980 with a model 5970 mass-selective detector was used for GC-MS. TGA measurements were performed on a Perkin-Elmer TGA-7 instrument. HPLC measurements were obtained using a Waters Instrument. 

To examine variation in the quality of methyl ketones expressed by females and newly-emerged males, we determined the number of unique methyl ketones expressed by individual snakes and compared the relative concentrations of individual methyl ketones comprising the overall pheromone profiles for the two groups. The methyl ketones present in the pheromone extracts were identified by gas chromatography / mass spectrometry (Hewlett Packard 5890 Series II gas chromatograph coupled with a Hewlett Packard 5971 Series mass selective detector— see LeMaster and Mason 2003 for full description of the GC/MS platform and methods). 

In the past decade, as systems have become simpler to operate, mass spectrometry (MS) has become increasingly popular as a detector for GC. Of all detectors for GC, mass spectrometry, often termed mass selective detector (MSD) in bench-top systems, offers the most versatile combination of sensitivity and selectivity. The fundamentals of MS are discussed elsewhere in this text. Quadrupole (and ion trap, which is a variant of quadrupole) mass analyzers, with electron impact ionization are by far (over 95%) the most commonly used with GC. They offer the benefits of simplicity, small size, rapid scanning of the entire mass range and sensitivity that make an ideal detector for GC. 

MS as a gas chromatographic detector has become much simpler to operate in the past decade. Nearly all control of the detector is performed through a data system with similar look-and-feel to other chromatographic data systems. Components such as ion sources now have less than 10 parts, making periodic cleaning and maintenance much simpler than in the past. Finally, the pricing of mass selective detectors is now similar to other selective detectors. It is likely that MS will eventually supplant most of the other selective detectors. 

Instrumentation Hewlett Packard supply the HP 5988A and HP 5987A mass-selective detectors for use with liquid chromatographs. 

HP 5988 A Mass selective detector HP 4987 A Mass selective detector Hewlett Packard PO Box 10301 Palo Alto... 

GC = gas chromatography GPC = gel permeation chromatography ECD = electron capture detector MS = mass spectrometry MSD = mass selective detector SFE = supercritical fluid extraction TLC = thin layer chromatography... 

Solutes were tentatively identified by atmospheric pressure ionization (API)-electrospray-mass selective detector (gas temperature 350°C, flow rate 101/min, nebulizer pressure 30 psi, quadrupole temperature 30°C, capillary voltage 3 500 V). 

Mass selective detector Outside of the scope of this chapter ... 

Other types of detectors such as mass selective detectors would need to have their own assessment performed. It should be clearly understood that the outcome of the risk assessment example is a personal assessment and is not meant to be definitive in any way. 

GC Conditions. Aldehyde derivatives were analyzed using a HP6890 gas chromatograph equipped with a mass-selective detector (5972A, Agilent Technologies, Palo Alto, CA) and fitted with a DB-5 capillary column, 30 m x 0.25 mm x 0.50 pm (J W Scientific, Folsom, CA). Helium was the carrier gas at a flow rate of 1.1 mL/min. 

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