Nebulizer dilution

Figure 10. Nebulizer/dilution system with Laskin-type nozzle in place...

Sea water and other saline waters pose some problems for the atomization methods. Nebulizers for the ICP tend to become blocked with salt encrustations with a disastrous effect on sensitivity. This can be overcome in direct analysis by flow injection techniques, or by the use of high-solids nebulizers. Dilution also helps here but, of course, degrades the detection limits. The sampling cone in ICPMS equipment is also prone to be gradually occluded when... 

ICP Excitation Source—Initiate the plasma soruce at least 30 min before performing an analysis. During this warm up period, nebulize dilution solvent. Inspect the torch for carbon build-up during the warm up period. If carbon build-up occurs, replace the torch immediately and consult the manufacturer s operating guide to take proper steps to remedy the situation. 

Analyze the test specimen solutions in the same manner.as the calibration standards (that is, same int ration time, background correction points (optional), plasnu conditions, etc.). Between test specimens nebulize dilution solvent for a minimum of 60 s. 

ICP Excitation Source—Initiate the plasma source at least 30 min before performing analysis. During this warm up period, nebulize dilution solvent Inspect the torch for... 

The detectable limits are given for samples such as they are introduced into the apparatus they should be previously diluted in order to be nebulized. It thereby is useful to apply a dilution coefficient, usually at least 10. The dilution depends on the sample viscosity. 

HR-ICP-MS EEEMENT-2 (Pinnigan MAT, Germany) equipped with a standard introduction system (quartz water-cooled spray chamber, concentric nebulizer, torch with 1.5 mm i.d. injector and nickel cones) was used for measurements. The following operating conditions were used RP power 1150 W, coolant gas flow rate 16 1 min k auxiliary gas flow rate 0.85 1 min nebulizer gas flow rate 1.2 1 min k Sample uptake rate was 0.8-1 ml min k Measurements were performed with low and middle resolutions. Rh was used as an internal standard. Por calibration working standard solutions were prepared by diluting the multielemental stock solutions CPMS (SPEX, USA) with water to concentration range from 5 ng to 5 p.g I k... 

Epinephrine is widely used in clinical medicine for its multiple pharmacologic effects particularly for its potent vasoconstrictor effects. For example, in a dilute solution of 1 100,000, it provides a surgical tourniquet and facilitates a blood-free operating field. It is administered by nebulizer and face mask for post-intubation croup and for viral croup. 

In cases of severe acute asthmatic attacks, bronchodilators and steroids for direct dehveiy to the lungs may be needed in large doses. This is achieved by direct inhalation via a nebulizer device this converts a liquid into a mist or fine spray. The dmg is diluted in small volumes of Water for Injections BP before loading into the reservoir of the machine. This vehicle must be sterile and preservative-fiee and is therefore prepared as a terminally sterilized unit dose in polyethylene nebules. 

More recent determinations of serum iron have been reported by Schmidt 57), who simply diluted with lanthanum chloride solution, and by Tavenier and Hellen-doorn58), who deproteinized samples in the latter study, iron in the protein precipitate is analyzed to correct the serum iron level. Uny etal. 59) determined serum iron, using ultrasonic nebulization of the sample to increase the sensitivity. Olson and Hamlin 6°) have determined serum iron and total iron-binding capacity. Proteins are precipitated and iron (III) is released by heating with trichloroacetic acid. 

By 1963, we had done considerable testing of LSD by the oral route, but we knew the military was more interested in the effectiveness of the respiratory route. Our first study of aerosolized LSD made use of an ancient Devilbiss nebulizer, a glass device relied on for decades by asthma sufferers. We partially filled its glass chamber with a very dilute solution of LSD in distilled water. 

The first aerosol experiments in this series utilizing quantitative techniques were performed by the writer in 1954. Two types of delivery were employed (a) powdered LSD diluted with talc, administered by means of a simple inertia device (Fig. la) (b) aqueous solutions of LSD administered intranasally by means of the nebulizer illustrated in Fig. lb. When a talc-LSD powder was administered intranasally, very severe reactions occurred rapidly. With a maximum dose of 256 meg delivered intranasally in the form of LSD-talc powder, subject J.M. had a most severe reaction, withdrawing to one part of my home in which the experiment took place and refusing to cooperate in his usual fashion. The data on Subject J.M. in this experiment are available. In order to study liquid aerosols, aqueous solutions of LSD-25 were administered intranasally to Subject J.M. The questionnaire was again used to estimate the severity of the reaction. The following technique of comparison was employed. 

The introduction of samples via nebulizers requires that they are either pneumatically or peristaltically pumped into the nebulizer for aerosol formation. This restricts the range of viscosities that can be easily handled by the nebulizer. For example highly saline or oil samples may well have to be diluted by an order of magnitude or greater. This dilution can be carried out either in a batch mode or continuously. Batch systems are quite complex in design but the rate of analysis is high. It is often the case that where dilution is required, in addition, a fast rate of analysis is also desirable. Some batch systems have been introduced commercially, notably to monitor wear metals in the oil industry. 

Samples were prepared for Cu isotope analysis on the Multicollector Inductively-Coupled Plasma Mass Spectrometer (MC-ICPMS) at University of Arizona. The Cu-rich samples were loaded and dissolved in pure HNO3 and the Cu-poor samples were loaded and dissolved in a mixture of HCI and HNO3, Chromatographic separation of the Fe and Cu ions was deemed necessary for the Cu-rich samples. The diluted solutions were injected into the MC-ICPMS using a microconcentric nebulizer. Samples were run numerous times to increase precision. The Cu isotope ratios are reported in conventional per mil notation, relative to the NIST 976 standard. Mass bias was also accounted for by bracketing methods with the NIST 976 standard. 

The samples purified with lEC were diluted to approximately 100 ppb Cu. These samples were injected into a Multicollector Inductively-Coupled-Plasma mass spectrometer (MC-ICPMS, Micromass Isoprobe at the University of Arizona and Neptune at Washington State University) in low resolution mode using a microconcentric nebulizer to increase sensitivity for the samples with lower concentrations of copper. The nebulizer flow was adjusted so that the intensity of the Cu beam remained constant at 2 volts. Both on and off peak blank corrections were applied to the data and yielded the same result. 

Hand bulb nebulizer 10 inhalations 5 to 15 inhalations No dilution... 

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. 

Potassium nebulize the extract without further dilution. 

Bronchospasm Hand-bulb Nebulizer 4 inhalations (range 3-7 inhalations) undiluted. Maybe repeated up to 5 times/day. Metered Dose Inhalation 1-2 inhalations q4h. Wait 1 min before administering 2nd inhalation. IPPB, Oxygen Aerosolization 0.5-1 ml of a 0.5% or 0.5 ml of a 1% solution diluted 1 3. 

Slurry nebulization has also proved very popular. In this technique, sample (typically 0.25 g) is placed in a 30 ml plastic bottle and 10 g of expanded zirconia beads are added. A dispersant is added and the bottle is sealed and then placed on a mechanical shaker for several hours. During the shaking, the zirconia beads grind the sample into very fine particles. After dilution to a known volume, the slurry may be aspirated directly into an atomic spectrometric instrument. Other methods of slurry preparation also exist, e.g. using a micronizer, but the bottle and bead method is the most common. 

Recommended dosage and monitoring requirements The recommended dose of Pulmozyme in most cystic hbrosis patients is 2.5 mg, inhaled once daily using a recommended nebuhzer. Some patients, however, especially those over 21 years old or with an FVC greater than 85%, may beneht from twice daily administration. Pulmozyme should not be diluted or mixed with other agents in the nebulizer. 

Albuterol, terbutaline, metaproterenol, and pirbuterol are available as metered-dose inhalers. Given by inhalation, these agents cause bronchodilation equivalent to that produced by isoproterenol. Bronchodilation is maximal within 15-30 minutes and persists for 3-4 hours. All can be diluted in saline for administration from a hand-held nebulizer. Because the particles generated by a nebulizer are much larger than those from a metered-dose inhaler, much higher doses must be given (2.5-5.0 mg versus 100-400 meg) but are no more effective. Nebulized therapy should thus be reserved for patients unable to coordinate inhalation from a metered-dose inhaler. 

Xopenex (levalbuterol HC1) inhalation solution is supplied in unit-dose vials and requires no dilution before administration by nebulization. Each 3-mL unit-dose vial contains either 0.63 mg of levalbuterol (as 0.73 mg of leval-... 

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