Can Emilie measure particle size?+
The infrared spectra recorded by EMILIE are independent of particle size. Thanks to compatibility with other imaging techniques, such as O-PTIR or SEM, the size of the nanoparticles in your sample can also be evaluated. The choice of method will depend on your sample.
Do I need to scan the surface of the Emilie nanomechanical sampling and sensing chip?+
No. NEMS-FTIR is a bulk characterization method. The entire surface of the EMILIE sampling and sensing nanomechanical chip is illuminated at once by the light source during a measurement.
If my sample is a mixture, will the resulting spectrum show the overlapping chemical fingerprints?+
Yes. NEMS-FTIR is a bulk characterization method. However, thanks to the broad spectral range EMILIE can provide additional information to help deconvolute the spectra. The necessary sample preparation prior to analysis to minimize spectral interferences will depend on the nature of your sample.
Can I analyze semi-volatile analytes with EMILIE?+
Yes. The EMILIE measurement chamber is evacuated down to a pressure 10-3 to 10-5 mBar during measurements. However, a Peltier element actively cools the EMILIE nanomechanical sensing chip during measurements to minimize evaporation and retain semi-volatile analytes on the surface.
Can I control the temperature of the EMILIE nanomechanical sensing chip during measurements?+
Yes. The temperature of the Peltier cooling element inside the EMILIE measurement chamber can be controlled from 5°C to 80°C. This feature can be used to retain semi-volatile analytes on the chipor to perform temperature stability and desorption experiments.
In which size range can EMILIE analyze nanoparticles?+
EMILIE can be used to chemically characterize nanoparticles with sizes below ca. 3000 nm. It is recommended to filter out larger particles prior to analysis or during sampling to avoid damaging the nanomechanical sensing element. If aerosol sampling is used as a method of sample collection, the lower limit for capturing aerosols is 10 nm. Refer to the sampling and handling guide in the Resources section for more information on sampling.
In which wavelength range can EMILIE operate?+
EMILIE’s sensitivity is independent of wavelength, so you can use it over the entire infrared range, from near infrared to far infrared. The only limitation is your light source and optics. The EMILIE measurement chamber is equipped with a diamond window to provide the broadest possible range.
Will water cause spectral interferences?+
No. NEMS-FTIR measurements with EMILIE are recorded under vacuum so that no water vapor will interfere with your spectrum.
Can I use spectral features of the EMILIE nanomechanical sampling and sensing chip as an internal standard in quantitative methods?+
Yes. The Emilie nanomechanical sensing and sampling chip is made out of silicon nitride. It features a large absorption peak at 866 cm-1 which can be used as an internal standard.
Can I use commercially available aerosol sampling systems to collect aerosols on EMILIE nanomechanical sampling and sensing chips?+
Yes. You can use our EMILIE sampling accessory and/or mini-MOUDI adapter to collect your aerosolized sample directly on the EMILIE nanomechanical sampling and sensing chips. Refer to the sampling and handling guide in the Resources section for more information on sampling.
What is the minimum amount of sample required to record a signal with Emilie?+
Limits of Detection (LoD) depend on the molecular absorptivity of your sample. The LoD for EMILIE in conjunction with a commercial FTIR is approximately a few hundred picograms. Refer to the sampling and handling guide in the Resources section for more information on sampling.
What is the maximum amount of sample that I can put on Emilie?+
You can do quantitative work with samples in the range of a few picograms to approximately 50 ng, depending on your specific sample. Samples as large as several hundred nanograms can be analysed with EMILIE.
Do I need to know the concentration of my sample prior to analysis with Emilie?+
No. You can do quantitative work with EMILIE. However, the initial concentration of your sample will affect the sampling procedure. High concentrations can easily overload the chip and may require dilution. Very low concentration solutions may require pre-concentration.
How long does it normally take to do one measurement?+
Measurements typically take approximately 5 minutes on an FTIR using the step scan mode. Evacuation of the measurement chamber in between measurements takes a few minutes when used in conjunction with the recommended turbomolecular pump.
