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Nebulization inlets

A typical arrangement for producing a particle beam from a stream of liquid, showing (1) the nebulizer, (2) the desolvation chamber, (3) the wall heater, (4) the exit nozzle, (5, 6) skimmers 1, 2, (7) the end of the ion source, (8) the ion source, and (9) the mass analyzer. An optional GC inlet into the ion source is shown. [Pg.78]

The nebulization and evaporation processes used for the particle-beam interface have closely similar parallels with atmospheric-pressure ionization (API), thermospray (TS), plasmaspray (PS), and electrospray (ES) combined inlet/ionization systems (see Chapters 8, 9, and 11). In all of these systems, a stream of liquid, usually but not necessarily from an HPLC column, is first nebulized... [Pg.79]

Suitable inlets commonly used for liquids or solutions can be separated into three major classes, two of which are discussed in Parts A and C (Chapters 15 and 17). The most common method of introducing the solutions uses the nebulizer/desolvation inlet discussed here. For greater detail on types and operation of nebulizers, refer to Chapter 19. Note that, for all samples that have been previously dissolved in a liquid (dissolution of sample in acid, alkali, or solvent), it is important that high-purity liquids be used if cross-contamination of sample is to be avoided. Once the liquid has been vaporized prior to introduction of residual sample into the plasma flame, any nonvolatile impurities in the liquid will have been mixed with the sample itself, and these impurities will appear in the results of analysis. The problem can be partially circumvented by use of blanks, viz., the separate examination of levels of residues left by solvents in the absence of any sample. [Pg.104]

Solutions can be examined by ICP/MS by (a) removing the solvent (direct and electrothermal methods) and then vaporizing residual sample solute or (b) nebulizing the sample solution into a spray of droplets that is swept into the plasma flame after passing through a desolvation chamber, where excess solvent is removed. The direct and electrothermal methods are not as convenient as the nebulization inlets for multiple samples, but the former are generally much more efficient in transferring samples into the flame for analysis. [Pg.108]

The term nebulizer is used generally as a description for any spraying device, such as the hair spray mentioned above. It is normally applied to any means of forming an aerosol spray in which a volume of liquid is broken into a mist of vapor and small droplets and possibly even solid matter. There is a variety of nebulizer designs for transporting a solution of analyte in droplet form to a plasma torch in ICP/MS and to the inlet/ionization sources used in electrospray and mass spectrometry (ES/MS) and atmospheric-pressure chemical ionization and mass spectrometry (APCI/MS). [Pg.138]

For solids, there is now a very wide range of inlet and ionization opportunities, so most types of solids can be examined, either neat or in solution. However, the inlet/ionization methods are often not simply interchangeable, even if they use the same mass analyzer. Thus a direct-insertion probe will normally be used with El or Cl (and desorption chemical ionization, DCl) methods of ionization. An LC is used with ES or APCI for solutions, and nebulizers can be used with plasma torches for other solutions. MALDI or laser ablation are used for direct analysis of solids. [Pg.280]

To assist in the deposition of these larger droplets, nebulizer inlet systems frequently incorporate a spray chamber sited immediately after the nebulizer and before the desolvation chamber. Any liquid deposited in the spray chamber is wasted analyte solution, which can be run off to waste or recycled. A nebulizer inlet may consist of (a) only a nebulizer, (b) a nebulizer and a spray chamber, or (c) a nebulizer, a spray chamber, and a desolvation chamber. Whichever arrangement is used, the object is to transfer analyte to the plasma flame in as fine a particulate consistency as possible, with as high an efficiency as possible. [Pg.400]

Special sample inlet devices such as nebulizers, furnaces, and gas inlets are commonly used to avoid cross-contamination and accidental fractionation of isotopes. [Pg.426]

These solutions are not always practicable and HPLC flow rates of up to 2 mlmin may be accommodated directly by the use of electrospray in conjunction with pneumatically assisted nebulization (the combination is also known as lonspray ) and/or a heated source inlet. The former is accomplished experimentally by using a probe that provides a flow of gas concentrically to the mobile phase stream, as shown in Figure 4.8, which aids the formation of droplets from the bulk liquid, and will allow a flow rate of around 200 p. min to be used. [Pg.160]

The sample solution is aspirated (drawn by vacuum) from its original container through a small tube and converted to an aerosol, or fine mist, prior to the mixing. These steps (aspiration and conversion to an aerosol) are accomplished with the use of a nebulizer at the head of the mixing chamber. The nebulizer is a small (3 cm long, 1 cm in diameter) adjustable device resembling the nozzle one places on the end of a garden hose to create a water spray. There are two inlets to the nebulizer. One inlet is a small plastic... [Pg.251]

The material of the nebulizer must be highly corrosion resistant. Commonly, the plastic capillary is fixed to a platinum-iridium alloy (90 10) capillary mounted in stainless-steel gas supply inlets. The impact bead is sometime made of a similar alloy or smooth borosilicate glass. [Pg.28]

Electrospray ionization is one of several variations of atmospheric pressure ionization (API) as applied to the outlet of an HPLC unit attached to the inlet of the mass spectrometer. These variations have in common the formation of a very fine spray (nebulization) from which the solvent can be quickly removed. The small particles are then ionized by a corona discharge at atmospheric pressure and swept by the continuous flow of the particles and a small electrical potential that moves the positively charged particles through a small orifice into the evacuated mass spectrometer. [Pg.11]

In order to combine reversed-phase LC with atmospheric pressure chemical ionization (APCI)-MS (125), a commercially available heated nebulizer interface that can handle pure aqueous eluents at flow rates up to 2 ml/min in addition to nonvolatile buffers has been used (126). The heated nebulizer inlet probe consists... [Pg.736]

Figure 22-17b provides more detail on ionization. Voltage imposed between the steel nebulizer capillary and the inlet to the mass spectrometer creates excess charge in the liquid by redox reactions. If the nebulizer is positively biased, oxidation enriches the liquid in positive ions by reactions such as... [Pg.488]

Arnoldsson and Kaufman optimized the response of the ELSD with a full factorial design evaluating the influence of evaporator temperature and air inlet pressure (70). As indicated in Fig. 10, the optimum conditions for both peak height and low baseline were achieved at high drift tube temperature and low-to-moderate nebulizer air pressure. The conditions chosen were 96°C and 1.6 bar. [Pg.273]

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. 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.
Figure 8.1. (A) CETAC ultrasonic nebulizers U-5000AT+ (1-15) and U-6000AT+ (1-19). 1 — transducer, 2 — aerosol chamber stand, 3 — aerosol chamber, 4 — sample/rlse adapter, 5 — U-tube, 6 — heat cords, 7 — glassware module, 8 — transducer radio frequency (RF) cable, 9 — sample inlet tubing, 10 — electronics module, 11 — auxiliary rinse port, 12 — operate switch, 13 — fast pump switch, 14 — heater controller (nebulizer), 15—cooler controller (nebulizer), 16 — heater controller (desolvator), 17 — flow meter, 18 — flow control and 19 — membrane desolvator controller. (B) Detailed scheme of the U-6000AT+ glassware module. (Reproduced with permission of CETAC Technologies.)... Figure 8.1. (A) CETAC ultrasonic nebulizers U-5000AT+ (1-15) and U-6000AT+ (1-19). 1 — transducer, 2 — aerosol chamber stand, 3 — aerosol chamber, 4 — sample/rlse adapter, 5 — U-tube, 6 — heat cords, 7 — glassware module, 8 — transducer radio frequency (RF) cable, 9 — sample inlet tubing, 10 — electronics module, 11 — auxiliary rinse port, 12 — operate switch, 13 — fast pump switch, 14 — heater controller (nebulizer), 15—cooler controller (nebulizer), 16 — heater controller (desolvator), 17 — flow meter, 18 — flow control and 19 — membrane desolvator controller. (B) Detailed scheme of the U-6000AT+ glassware module. (Reproduced with permission of CETAC Technologies.)...
Liquid sampies are inserted into the two commerciai USNs through the inlet tubing by pumping with, for exampie, a peristaitic pump. For this reason, these nebulizers are frequently said to operate in the continuous mode [23]. The inlet tube also allows the USN to be used as an interface between a flow system, where other steps of the analytical process can be developed, and the detector. CETAC USNs have been used in official methods of analysis such as US-EPA Method 200.15 for the determination of metals and trace elements in water by USN-ICP-AES [24]. [Pg.258]

The nano-electrospray (nanoES) source is essentially a miniaturized version of the ES source. This technique allows very small amounts of sample to be ionized efficiently at nanoliters per minute flow rates and it involves loading sample volumes of 1-2 pi into a gold-coated capillary needle, which is introduced to the ion source. Alternatively for on-line nanoLC-MS experiments the end of the nanoLC column serves as the nanospray needle. The nanoES source disperses the liquid analyte entirely by electrostatic means [27] and does not require assistance such as solvent pumps or nebulizing gas. This improves sample desolvation and ionization and sample loading can be made to last 30 minutes or more. Also, the creation of nanodroplets means a high surface area to volume ratio allowing the efficient use of the sample without losses. Additionally, the introduction of the Z-spray ion source on some instruments has enabled an increase in sensitivity. In a Z-spray ion source, the analyte ions follow a Z-shaped trajectory between the inlet tube to the final skimmer which differs from the linear trajectory of a conventional inlet. This allows ions to be diverted from neutral molecules such as solvents and buffers, resulting in enhanced sensitivity. [Pg.2196]

Interfacing micro-LC and MS via a capillary inlet interface coimected to a GC-MS jet separator was described in 1978 by Takeuchi et al. [55]. In the period until 1982, this system was subsequently developed towards a vacuum nebuhzer, in which the column effluent is pneumatically nebulized into a modified jet-separator type of device [56-57]. The instrumental developments of the vacuum nebulizer interfaces are discussed in Ch. 4.3. Pneumatic nebulization of column effluents directly into the Cl somce was described by a number of groups [58-61]. A so-called helium interface for the introduction of organic solvents was described by Apffel et al. [59]. It was primarily applied to the analysis of pesticides in aqueous samples. Although the system was commercially available, it did not find wide application. [Pg.59]

Over 30 years of liquid chromatography-mass spectrometry (LC-MS) research has resulted in a considerable number of different interfaces (Ch. 3.2). A variety of LC-MS interfaces have been proposed and built in the various research laboratories, and some of them have been adapted by instmment manufacturers and became commercially available. With the advent in the early 1990 s of interfaces based on atmospheric-pressure ionization (API), most of these interfaces have become obsolete. However, in order to appreciate LC-MS, one carmot simply ignore these earlier developments. This chapter is devoted to the older LC-MS interfaces, which is certainly important in understanding the histoiy and development of LC-MS. Attention is paid to principles, instrumentation, and application of the capillary inlet, pneumatic vacuum nebulizers, the moving-belt interface, direct liquid introduction, continuous-flow fast-atom bombardment interfaces, thermospray, and the particle-beam interface. More elaborate discussions on these interfaces can be found in previous editions of this book. [Pg.73]


See other pages where Nebulization inlets is mentioned: [Pg.38]    [Pg.56]    [Pg.67]    [Pg.139]    [Pg.150]    [Pg.830]    [Pg.388]    [Pg.60]    [Pg.29]    [Pg.118]    [Pg.233]    [Pg.242]    [Pg.202]    [Pg.188]    [Pg.230]    [Pg.318]    [Pg.55]    [Pg.54]    [Pg.6086]    [Pg.53]    [Pg.258]    [Pg.407]    [Pg.202]    [Pg.64]   
See also in sourсe #XX -- [ Pg.108 ]

See also in sourсe #XX -- [ Pg.108 ]




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