Nano-spray

Li, X., Anton, N., Arpagaus, C., Belleteix, R, and Vandamme, T.R Nanoparticles by spray drying using innovative new technology The Biichi Nano Spray Dryer B-90. Journal of Controlled Release 147(2) (2010) 304-310. 

Mass spectrometer High performance mass spectrometer capable for high resolution measurements of at least precursor peptide masses and MS/MS possibilities (e.g., Q Exactive Hybrid Quadrupole-Orbitrap Mass Spectrometer, Thermo Scientific) equipped with a nano-spray source (e.g.. Nanospray Flex Ion Source, Thermo Scientific) see Note 2). 

In order to tailor the physical properties of nano-particles, wet granulation was conducted. Hydroxypropylecellulose (HPC-L) 5% aqueous solution was sprayed onto nano-sized Ti02 particles through a binary nozzle. Fluidization air velocity was set at approximately 1.5 times as large as the minimum fluidization air velocity. 

Precipitation/Crystallization to Produce Nano- and Microparticles Because fluids such as C02are weak solvents for many solutes, they are often effective antisolvents in fractionation and precipitation. In general, a fluid antisolvent may be a compressed gas, a gas-expanded liquid, or a SCF. Typically a liquid solution is sprayed through a nozzle into CO2 to precipitate a solute. As CO2 mixes with the liquid phase, it... 

The ionspray (ISP, or pneumatically assisted electrospray) LC-MS interface offers all the benefits of electrospray ionisation with the additional advantages of accommodating a wide liquid flow range (up to 1 rnl.rnin ) and improved ion current stability [536]. In most LC-MS applications, one aims at introducing the highest possible flow-rate to the interface. While early ESI interfaces show best performance at 5-l() iLrnin, ion-spray interfaces are optimised for flow-rates between 50 and 200 xLmin 1. A gradient capillary HPLC system (320 xm i.d., 3-5 xLmin 1) is ideally suited for direct coupling to an electrospray mass spectrometer [537]. In sample-limited cases, nano-ISP interfaces are applied which can efficiently be operated at sub-p,Lmin 1 flow-rates [538,539]. These flow-rates are directly compatible with micro- and capillary HPLC systems, and with other separation techniques (CE, CEC). 

For a 75 /.mi ID nano LC column as an example, the MS detection enhancement factor (ion count) in comparison to a 4.6 mm column is much higher than (4.6/0.075)2 = 3761 because of the reduction in sample molecular zone dilution and because a nano LC solvent flow rate at 0.02 to 2 /iL/min can be 100% directly sprayed into the MS ion source. No post-column flow splitting is required for nano-LC-MS as that required when 1 mL/min is used in a 4.6 mm ID column. This large enhancement of MS detection and the ability to directly interface with MS presents nano LC-MS as the best tool for life science research. 

Because of the short liquid flow path of nano LC and the small orifice spray tip of the MS interface, column and flow path plugging is a common problem with nano LC-MS. Sample clean-up is critical for ensuring reliable daily operation and generation of quality data. Online desalting and particle filtering are particularly important steps. Four online sample clean-up factors should be considered with nano LC ... 

Fig. 11.5. Nano-electrospray (a) SEM micrograph of the open end of a glass nanoESI capillary having a 2-pm aperture, (b) microscopic view of the spray from a nanoESI capillary as provided by observations optics. By courtesy of New Objective, Woburn, MA.

Hayasaka et al. [157] reported the determination of the fatty acid distribution in mouse retina by using AgNPs in nano-PALDI-IMS. The sections were sliced to a thickness of 10 pm and sprayed with AgNPs or DHB matrix solution at 50 mg/mL in 70 % methanol/0.1%TFA. The mouse retinal sections were analyzed at a high spatial resolution with a scan pitch of 10 pm. The MS images showed the distribution of palmitic acid, linoleic acid, oleic acid, stearic acid, eicosapentaenoic acid (EPA), arachidonic acid, and docosahexaenoic acid (DHA). 

Desorption nano-electrospray (nano-DESI) has also been tested for qualitative analysis of anthocyanins in wine samples (Table 5.1 Method 5) (Hartmanova et ah, 2010). Acidifying of the samples and providing an acidic spray liquid (methanol/water 75 25 with 0.2% HCOOH) were essential for obtaining good quality spectra. From the nano-DESI-MS data, the ratio of two grape cultivars (Neronet and Rubinet) in a mixture could be determined. Detection of the main anthocyanins in slices of wine grapes, chokeberries, and elderberries or in a wine stain on cotton fabric was also possible (Hartmanova et al., 2010). 

Dry methods and postcalcination methods The industrial micron sized R2O3 powder is commonly made by thermal pyrolysis of rare earth carbonates or oxalates at a temperature of 600-1000 °C. The dry methods usually result in fine powders with a relatively wide size distribution. After the sintering, the surface OH and other solvent related species are generally removed, therefore, the powder may exhibit better luminescence efficiency and longer decay time. Nano-sized rare earth oxide products could be obtained from finely selected precursors like hydroxides gels, premade nanostructures, through heat treatment, spray pyrolysis, combustion, and sol-gel processes. 

Non-analytical uses of US-assisted nebulization span the medicai and pharmaceutical fields, where aerosoling or aerolization is more frequentiy used than nebuiization [67,68], The use of uitrasound to assist the formation of micro-to-nano drops as the first step of spray-drying (atomization) aiso faiis in this group, aibeit in the industriai area. 

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