Sampler cone

One of the first reported couplings of GC-ICP-MS was by Van Loon et al. [115], who used a coupled system for the speciation of organotin compounds. A Perkin-Elmer Sciex Elan quadrupole mass filter instrument was used as the detector with 1250 or 1500 W forward power. The GC system comprised a Chromasorb column with 8 ml min 1 Ar/2 ml min-1 02 carrier gas flow with an oven temperature of 250°C. The interface comprised a stainless-steel transfer line (0.8 m long) which connected from the GC column to the base of the ICP torch. The transfer line was heated to 250°C. Oxygen gas was injected at the midpoint of the transfer line to prevent carbon deposits in the ICP torch and on the sampler cone. Carbon deposits were found to contain tin and thus proved detrimental to analytical recoveries. Detection limits were in the range 6-16 ng Sn compared to 0.1 ng obtained by ETAAS, but the authors identified areas for future improvements in detection limits and scope of the coupled system. 

Figure 1 Schematic diagram of a typical commercial inductively coupled plasma mass spectrometry (ICP-MS) instrument (A) liquid sample, (B) peristaltic pump, (C) nebulizer, (D) spray chamber, (E) argon gas inlets, (F) load coil, (G) sampler cone, (H) skimmer cone, (I) ion lenses, (J) quadrupole, (K) electron multiplier detector, (L) computer.

Cjg, C8, or Cj siloxane stationary phases may be used for reversed-phase separations. Mobile phases of high pH values should be avoided as hydrolysis of the siloxane stationary phase occurs and so the packing material degrades over time. Phosphate or acetate buffers may be used to control the pH of the mobile phase, although the concentration of these salts should be kept to a minimum so that clogging of the torch injector and sampler cone does not occur. 

Low-pressure He-ICPs have been used as chromatographic detectors for mass spectrometry [111,112,114], Organotin compounds [112] were speciated by using a plasma operated at 100 W. A low-pressure torch must be constructed from a quartz tube of dimensions approximately 150 mm long and 6 mm outer diameter to sustain such a plasma. This torch is connected at one end to the GC interface and to the sampler cone at the other. Heated transfer lines must be used for reproducible transfer of the GC analytes. As the low-pressure system may not completely at-... 

The cost of running an ICP-MS is quite high. Ar is expensive, especially so because it is used in large volumes. Moreover, spare parts like skimmer and sampler cones, torches, and detectors have a limited lifetime. ICP-AES and ICP-MS have similar Ar consumptions. On the other hand, the former technique is somewhat cheaper to mn since the replacement rate of consumables is lower. The different forms of AAS require various amounts of different gases. These are, however, far less than the volumes consumed by the competing techniques. The cost for other items such as graphite tubes and cones is fairly moderate. All three techniques require service at regular intervals, which is in itself rather expensive. 

Sn Bu2Sn +, Bu3Sn+, Pli2Sn + and Pli3Sn Harbor sediment Reversed phase Kromasil-100 15 cm X 2.1 mm, 5 pm APCI-MS ICP-MS Triethylamine used to improve chromatography for BusSn mass spectra for different OTCs reported low flow rate, oxygen added post-nebulization, chilled spray chamber and Pt sampler cone used for ICP-MS 1998 438... 

The FAIMS analyzer was interfaced to a PE Sciex API 300 triple-quadrupole MS. Ions were filtered through the FAIMS and introduced into the MS through a sampler cone that was placed at the end of the FAIMS analyzer at a 45° angle relative to the axis of the FAIMS cylinders. Using this instrument, the high-field mobility of conformer ions, ions of multiple charge states, and complex ions of leucine enkephalin were investigated. ... 

It should be noted that for most sample matrices, it is desirable to keep the TDS below 0.2%, because of the possibility of deposition of the matrix components around the sampler cone orifice. This is not such a serious problem with short-term use, but it can lead to long-term signal instability if the instrument is being run for extended periods of time. The TDS levels can be higher (0.5-1%) when analyzing a matrix that forms a volatile oxide such as sodium chloride because, once deposited on the cones, the volatile sodium oxide tends to revaporize without forming a significant layer that... 

FIGURE 5.3 Close-up of a platinum sampler cone (left) and a platinum skimmer cone (right) (courtesy of Spectron Inc.). 

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