Submit Your Request Now

Fast Atom Bombardment

Fast atom bombardment (FAB) is an ionization technique established in 1981, which is widely used as an ion source in mass spectrometry systems. Unlike other ionization techniques, FAB bombards a sample with a neutral atom (Xe, Ar) to ionize the sample. The use of neutral atoms avoids the accumulation of charge in the insulating sample and facilitates ionization of the sample. FAB can successfully determine compounds that are not volatile or derivatized, as well as some polymer compounds. Moreover, FAB is effective for the determination of oligosaccharides, oligopeptides, oligonucleotides, and thermally labile organic compounds and even metal organic compounds.

The Principle of FAB

The FAB directly bombards the surface layer of the sample with a high-speed directional movement of neutral atoms, ionizing the sample to form positive ions [M+H]⁺, negative ions [M+H]^-, and fragment ions. The FAB ion source consists of a cold cathode release ion gun and a collision charge exchange chamber. Ar is ionized in the release ion gun to form Ar⁺, and then Ar⁺ forms a high speed Ar⁺ ion beam under the action of the accelerating voltage and the focusing electrode. The charge exchange chamber is filled with Ar. When the ion beam enters the exchange chamber, the following reaction occurs:

"< >" indicates a particle symbol with rapid directional motion. The fast directional motion of Ar⁺ acquires electrons from Ar, forming Ar for rapid directional motion. The energy loss of ＜Ar⁺＞ during charge exchange is small, so the resulting ＜Ar＞ also has a high energy. ＜Ar⁺＞ is separated in the deflection electric field, and ＜Ar＞ is still advancing at a high speed in the original direction, and finally hitting the sample target to ionize the sample:

Fast Atom Bombardment

The sample is dissolved in a solvent and applied to a tiny piece of metal in the FAB. The vapor pressure of the solvent used should be low enough to keep the sample in a dissolved state. The solvent used includes glycerin, diethanolamine, ethylene glycol, dimethyl sulfoxide or the like.

Fast Atom Bombardment Figure1. Schematic of FAB ion source

After the sample is ionized, its positive charge product is mostly present in the form of proton bonding or alkali metal ion binding. Generally only a small amount of alkali metal ions are needed, and a [M+Na]⁺ or [M+K]⁺ signal can appear in the mass spectrometer. The [M+Na]⁺ peak was first observed in samples (polypeptides) with strong basic groups. If the sample is mixed with acid, the signal is strengthened. On the other hand, the anionic product appears in the form of [M-H]^-. Acid samples are often ionized into [M-H]^-, and salt samples form a charged ion by cleaving a cation or anion. The literature indicates that salt ions are important for determining the molecular weight of a sample and analyzing its structure.

Advantages and Disadvantages of FAB

FAB is very effective for the analysis of non-volatile, thermally unstable polar compounds. The ionization products [M+H]⁺ and [M-H]^- are produced in pairs in FAB, facilitating the analysis of positive ion mass spectrometry and negative ion mass spectrometry. The FAB has high sensitivity and consumes less sample. The minimum measured molecular weight of the sample can be several 10^-9g, and the utilization rate of the sample is high. For biologically active substances, the residual sample remains active and can be recycled due to the bombardment of the neutral particles used. In addition, the ionization probability and detection sensitivity of each component in the sample are related to the sample composition. If the energy required for ionization of one component is lower than the other components in the sample, the ionization probability of the component is large.

However, FAB is not suitable for separating samples. It is difficult for FAB to separate the sample with low affinity proton abilities from samples with high affinity proton abilities. Moreover, for samples of mixtures of different volatility, FAB cannot fractionate and ionize the components.

Applications of FAB

As a mass spectrometry ionization source, FAB is suitable for the analysis of highly polar, thermally unstable compounds, especially peptides and proteins. The application of FAB-MS tandem technology provides detailed sample molecular structure information and is widely used in biomedical fields. Among the peptide compounds, FAB successfully analyzes thousands of molecular weight macromolecules, and gives the order and type of amino acids in the polypeptide, and also distinguishes the isomers of the polypeptide, such as cephalin, human gastrin, bovine insulin, bradykinin, adrenocorticotropic hormone and so on. In addition, FAB can measure polar antibiotics such as neomycin, streptomycin, gentamicin, erythromycin, oxytetracycline and so on. In the analysis of compounds for nucleotides and their phosphates, FAB successfully analyzes nicotinamide adenine dinucleotide phosphate (C₂₁H₂₉N₇O₁₇P₃) and vitamin B₁₂ (C₆₃H₈₈CoN₁₄O₁₄P).

Thermally unstable polar organic compounds are substances that are difficult to vaporize and decompose easily. Based on ionization technology of inert atoms, FAB provides an effective solution for the analysis of such compounds. In conjunction with mass spectrometry, FAB has made significant advances in quantitative analysis and structural analysis. With the continuous development of mass spectrometry technology, the application field of FAB will be further expanded.

We have briefly introduced the FAB, a type of ionization methods, which can help you understand more about mass spectrometry. At Creative Proteomics, we have the professional mass spectrometry platform, which contains different instruments. By using mass spectrometry, Creative Proteomics can provide different services to meet various requirements, including:

References

Barber M, et al. Fast atom bombardment of solids as an ion source in mass spectrometry. Nature, 1981, 293(5830):270-275.
Pramanik B N, et al. Structural characterization of the oligosaccharide antibiotics everninomicins by negative ion FAB and ESI/MS. Journal of Antibiotics, 2000, 53(6):640-3.
Walton T, et al. Differentiation of Isomeric Purine and Pyrimidine Mononucleotides by Fast Atom Bombardment Tandem Mass Spectrometry. Nucleosides & Nucleotides, 2012, 9(7):967-983.
Barber M, et al. Fast atom bombardment mass spectrometry of bradykinin and related oligopeptides. Biological Mass Spectrometry, 2010, 8(8):337-342.

* For Research Use Only. Not for use in diagnostic procedures.

Our customer service representatives are available 24 hours a day, 7 days a week. Inquiry

From Our Clients

"I recently used their proteomics service for a project analyzing protein interactions in yeast models. The team was very responsive and helped clarify the methodology they employed, which made me feel confident in the results. The data quality was solid, with clear identification of several key proteins involved in our study. Their thorough analysis enabled me to pinpoint specific interactions that I hadn't considered before, which significantly improved the direction of my research. I appreciate their professionalism and support throughout the process."

Sarah Thompson, University of California, Berkeley

"Our lab collaborated with them on a project studying cancer biomarkers. The proteomics analysis provided was detailed and focused, specifically highlighting the differential expression of proteins between healthy and tumor samples. Their clear explanations of the data helped my team understand the biological implications. I also appreciated their willingness to revise the reports based on our feedback, ensuring that we had everything we needed for our publication. This collaborative spirit was invaluable."

Emily Rodriguez, Stanford University

"Our lab worked with them on a project studying the effects of diet on gut microbiota using proteomics. They used a label-free quantification method to analyze proteins in fecal samples before and after dietary intervention. The results showed significant changes in protein expression linked to microbial activity. This was pivotal for our hypothesis about diet-microbiota interactions. The clarity of their data presentation made it easy for our team to integrate these findings into our ongoing research."

Dr. Lisa Wong, University of Toronto

"My experience with Creative Proteomics during the mass spectrometry analysis was excellent. We sent in human saliva and mouse brain tissue samples, which they expertly analyzed using both LC-MS and GC-MS techniques. The results were invaluable, revealing key metabolites in the saliva and identifying biomarkers linked to brain function in the brain tissue."

Dr. Emily Carter, Senior Research Scientist

"The overall service from Creative Proteomics was outstanding. They made the entire process seamless and efficient, allowing us to focus on our research. We worked with leaf and root samples from various Arabidopsis genotypes for targeted metabolomics analysis. Their thorough profiling of primary and secondary metabolites gave us important insights into how the plants respond metabolically to environmental stress."

Dr. Laura Henderson, Plant Physiologist

"We had a pleasant collaboration with Creative Proteomics on mass spectrometry analysis of lipids. They conducted a detailed analysis of lipid species, providing us with important insights into lipid metabolism and its relationship with metabolic syndrome disease states."

Dr. Sarah Mitchell, Research Scientist

Online Inquiry

Please submit a detailed description of your project. We will provide you with a customized project plan to meet your research requests. You can also send emails directly to for inquiries.

Great Minds Choose Creative Proteomics