Continuous nebulization

Monitor serum potassium in patients receiving high-dose or continuous nebulization of a short-acting p2-agonist. Serum potassium concentrations should be obtained upon admission, and if hypokalemic, every 4 hours (after each 30 to 40 mEq or mmol of replacement) until the patient s potassium is stable. Potassium should be monitored every 3 to 6 months after discharge. 

Continued nebuiization Continued nebulization of acetylcysteine with a dry gas results in concentration of drug in the nebulizer due to evaporation. Extreme concentration may impede nebulization and drug delivery. Dilute with Sterile Water for Injection as concentration occurs. 

Maggs [36] developed an electron-capture detector (ECD) which was based 6n the moving wire transport system. This type of detector is now available commercially (Table 3.5). Nota and Palombardi [37] described a system in which the column eluent was continuously nebulized and part of which was directed into the interior of an ECD. 

Figure 3 Effect of discrete sample volume aspirated and of continuous nebulization on the photomultiplier signals in AAS for a l mg l 1 magnesium solution...

Conventional pneumatic nebulizers typically consume sample solution at the rate of ca. 5-8 ml min-1. Thus generally, when flame spectrometry is used on a routine basis, 2-5 ml of sample solution is used per determination. However it is possible to employ much smaller volumes of sample solution.16 Figure 3, for example shows typical atomic absorption signals for the nebulization of 0.01, 0.02, and 0.05 ml of a 1 mg l-1 standard solution, as recorded on a storage oscilloscope, compared with the signal from continuous nebulization. It is clear that only about 0.04 ml of solution is required to obtain the maximum absorbance signal. 

An ICP-MS instrument will not tolerate dissolved solids at concentrations that can be run with an ICP-atomic emission spectrometer. In addition to increasing the probability of interelement (isobaric) interferences and signal suppression, high levels of dissolved solids condense on the sample-cone orifice. This deposition degrades the sensitivity and stability of the analytical signal. Typically, a maximum of 0.1% dissolved solids is recommended for continuous nebulization with a pneumatic... 

The AeroEclipse (Monaghan/Trudell International) shown in Fig. 9, is a nebulizer powered by compressed air, which can be operated in both continuous nebuli-zation and breath-actuated modes. The nebulizer was characterized, in vitro, using different breathing patterns, with either continuous nebulization or breath-actuated nebulization. A piston pump was used to... 

The AAS method has several limitations. For the trace elements, particularly the colorants cobalt and nickel, the dilution factor required for analyses of 12 elements by continuous nebulization places these elements close to the detection limits for flame AAS. More accurate data on these and other trace elements are necessary before conclusions can be drawn on the source minerals used to impart color. Phosphorus, a ubiquitous minor component of medieval stained glass, has not been determined by AAS in the course of this work, but has the potential to provide key information on sources of plant ash. A full understanding of the colorant role of the transition metal elements is not possible on the basis of analysis alone UV-visible spectroscopy, electron spin resonance spectrometry, and Mossbauer spectroscopy, for example, are necessary adjuncts to achieve this aim. The results of the application of these techniques and the extension of the AAS method to trace element determination by pulse nebulization and furnace atomization will be addressed in future reports. 

DD is a 70-year-old woman admitted to the hospital for exacerbation of her COPD. She is currently intubated and receiving high-dose albuterol therapy by continuous nebulization. Which of the following adverse effects may be associated with this treatment ... 

Numerous studies have shown that the inhaled /32-agonists administered by MDI plus holding chamber provide a similar outcome in severe acute asthma as administration by jet nebulizers. Proponents of administration by MDI plus holding chambers argue that it is more cost-effective and so should replace nebulizer therapy. However, appropriate cost analyses have yet to be performedNor have there been comparisons in the most severe subsets, where combination therapy and continuous nebulization are recommended. Current practice should be based on the comfort level of the clinical staff until sufficient data are available to warrant a wholesale recommendation of one method. 

Table XII. Detection limits obtained with an SIT from 100 uL samples compared to continuous nebulization and compared to AAS detection limits.

Earlier FAAS techniques for measuring serum copper levels which included protein precipitation with trichloroacetic acid (Olson and Hamlin, 1968) and/or solvent extraction have been superseded by simpler procedures using either large sample dilution or viscosity adjusted reference solutions with minimal dilution. The analyses are made mainly using continuous nebulization, discrete sample injection or by flow injection techniques with little advantage gained from flame adaptors to increase sensitivity. 

The German "Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area, Working Group Analytical Chemistry" has developed a continuous nebulization FAAS method for copper in serum based on a 1 -r- 1 dilution (dilution depends on the applied burner system) with a determination limit of 0.1 mg/L At a mean copper concentration of 1.24 mg/L the within batch precision was 2.4% and the day-to-day precision 3.2% (Winter and Schaller, 1985). Accuracy was checked against certified reference materials. The method was applied on fortified samples from a serum pool of healthy persons and compared by a GF/ AS method developed and tested at the same time (Angerer et al., 1985). The FAAS method is still in successful routine use in a number of German laboratories because of its reliability, simplicity and speed (Schaller, 1993). 

McPeck M, Tandon R, Hughes K, Smaldone GC. Aerosol delivery during continuous nebulization Chest 1997 111 1200-1205. 

Gelinas,Y, Lenjer, R., and Schmit, J.-P. (1996). Optimally interfacing an ICP-MS with a conventional autosampler for the analysis of solutions with a high dissolved solids content using continuous nebulization. At. Spectrosc. 17(4), 143. 

Pattberg, S., and Matschat, R. (1999). Determination of trace impurities in high purity copper using sector-field ICP-MS Continuous nebulization, flow injection analysis and laser ablation. Presenius J. Anal. Chem. 364(5), 410. 

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