January 10, 2024
Description
They […] have transformed my wildest dreams into a reality even more unbelievable
than “flying elephants!” - John B. Fenn at Nobel lecture 2002.
Electrospray is a process where molecules from a liquid phase are ionized and transitioned into the gas phase for further analysis by methods such as mass spectrometry or ion mobility spectrometry. This process is possible for small molecules up to large molecular machines such as proteins. In an electric field the solvent is emitted through a needle. The solvent evaporates until the charged droplets explode and release the molecular ions into the instrument where the charged ions are guided by electric fields and analyzed in greater detail.
Nano electrospray is a variation of electrospray with minimum flow (nanoliter per minute). This is achieved through emitter needles with a small opening in the micrometer range. Such emitters can be produced by pulling heated glass capillaries which are subsequently metal-coated.
By default, most Bruker mass spectrometers such as the timsTOF or the amaZon speed ETD come with an ESI source for higher flow rate. This so-called ionBooster source block is used to attach the provided model. There is no commercially available adapter for Bruker instrument that would enable nanoESI using coated glass capillaries. We therefore devised a simple design that enables easy access to the capillary and provides optimal positioning of the emitter tip close to the mass spectrometer entrance.
This source add-on is not an official product of Bruker. Usage of the model on any instrument is at your own risk. The publisher can not be held responsible for damage to any instrument or person when using this assembly. At the source, a high voltage is applied. Any handling of the source should only be done when source voltages are turned off. Additional warning labels should be added indicating high voltage operation.
Please see the BOM.csv file for a list of required non-printed parts. Also check out the peer-reviewed manuscript in the Journal of the American Society of Mass Spectrometry (JASMS) here.
Use two 608 ball bearings and push them in place in the front plate as well as the Z-wheel holder. These ball bearings can also be printed as such or as dummies (8 x 22 x 7). Proceed by fitting the Z-wheel to the T8-threaded rod. It is recommended to do this on a rubber-faced vice holding the rod. Place the Z-wheel in the center of the Z-wheel holder. Optionally, two 8 mm washers can be placed on both sides of the wheel. Install the rod to be flush with the back wall of the Z-wheel holder.
Install the T8-threaded insert that should come with the threaded rod on the sled base with two M3x20 screws and two hex nuts.
Install the two linear rods, slide the sled on and move it towards the Z-wheel holder by turning the Z-wheel clockwise, once the rod caught the threaded insert.
Assemble the base with four M3x10 screws, four square nuts pressed into the grooves of the front plate and the Z-wheel holder as well as two M3x20 screws and two hex nuts in the Z-wheel holder.
Next install the two small MR84 ball bearings in the sled base and the Y-gear holder. Install the Y-gear B in the holder and tighten it with two M3x10, one M3x30 and three M3 square nuts pushed in place in the Y-gear holder.
Place Y-gear A in the grove of the Swagelok adapter and fix it on the sled using two M3x10 screws and 2 square nuts pushed into the Swagelok adapter.
use a spring from a ball pen and slide it over an M3x20 screw. Put it in the slit on the back end of the Swagelok adapter. It will act as a counterforce to position the emitter in the X-direction. install an M3x30 screw on the right side of the sled using an M3 square nut. Glue the X-knob onto that screw. Push the Y-knob onto Y-gear B.
Assemble the emitter holder by attaching the steel tube adapter (Swagelok SS-400-6-1) to an 80 mm ¼'' metal tube. Push this emitter holder through the front of the Swagelok adapter. It should fit tightly in the hexagonal groove. Push the nebulizer adapter onto the back of the ¼'' tube.
Detach the blue plastic cover of the Bruker ionBooster source block and remove one of the two side windows. Use the original screws (without washer) to attach the assembly on the opening of the source block. To connect the emitter electrically to GND, the upper screw can be used to fix a wire using a cable lug. The wir can then either be clamped between the Swagelok holder and the emitter holder or attached to the ¼'' rod using a crocodile clamp. Connect the nebulizer gas tubing to the nebulizer adapter on the back. The assembly is ready to be used.
Recommended initial settings for using the offline nanoESI source:
V (End plate offset) = 0.5 kV
V (Capillary) = 1.3-1.8 kV
P (Nebulizer) = 0.5-1.5 bar
Reference
The source was also recently published in JASMS as Open Access: https://pubs.acs.org/doi/10.1021/jasms.3c00214
License:
Creative Commons — Attribution — Share Alike
9
PagelGroup
