Reference Materials for Mass Spectrometry - Raise your Standards with Cayman Chemical | Biomol Blog | Resources

Written by Emily Locke

Detect coke in a fingerprint? Yes, you can! In fact, fingerprints not only tell researchers who the criminal was, but even what they last touched. Thanks to modern technology, it is possible to precisely reproduce the chemical composition of the print and thus detect traces of explosives or narcotics, for example. In addition, overlapping fingerprints can be easily distinguished using this technique, which is a major problem with other conventional methods. It is therefore no wonder that the Federal Criminal Police Office is following research on this type of testing methods with great interest [1]!

But what exactly is this method? It has the somewhat bulky name "desorption electrospray ionization mass spectrometry" - or DESI-MS for short - and is one of the many different variants of mass spectrometry (MS). MS is an extremely versatile and at the same time very powerful analytical method that is used in a wide variety of areas - including forensic investigations. Due to its high relevance, it was even named method of the year 2012 by the scientific journal Nature Methods [2]. In general, MS is a method for measuring the mass of ions, atoms or molecules, which makes it possible to clearly identify substances [3]. Sounds exciting? Our supplier Cayman Chemical offers you more than 2000 reference standards as well as the MaxSpec® product range developed specifically for MS, in which you will find a wide selection of high-quality analysis kits and standards for a wide variety of MS applications!

These topics await you:

1) A technologically advanced Scale: How does Mass Spectrometry work?

2) Diversity in Variation – The great Strength of Mass Spectrometry

3) All about Patterns: What does a Mass Spectrum tell us?

4) Accelerated MS Analyses with Cayman Chemical

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A technologically advanced Scale: How does Mass Spectrometry work?

As the name suggests, mass spectrometry is about determining the mass of a specific ion. To do this, the substance to be examined, the analyte, is first transferred into the gas phase (desorption) and ionized. The ions are then accelerated by an electric field and fed to an analyzer, which sorts them according to their mass-to-charge ratio m/z or m/q (Fig. 1). The particles can also be fragmented, which is often desirable for complex biopolymers in particular, as fragments can be more easily transferred into the gas phase. Mass spectrometry is used in biochemistry to investigate biomolecules, such as proteins, but also in the characterization of chemical compounds, in medical chemistry to identify substances in body fluids or organs, in environmental analysis and even in doping controls [4].

MassSpec_Figure1_new

Figure 1: Setup of a mass spectrometer. The analyte is first transferred to the gas phase in the evaporation chamber and then ionized in the ion source (here by bombardment with an electron beam). The ions are then extracted using an electric field, accelerated and fed to the analyzer. This separates the ions according to their mass-to-charge ratio, e.g. by using a plate capacitor and a magnetic field. Finally, the separated ions hit the detector. The recorded data can be used to determine the mass of the individual particles (image created with biorender.com).

Many different variants are available for each component of a mass spectrometer, so that application-specific mass spectrometers can be constructed by combining different components [3]. Essentially, however, a mass spectrometer always consists of an ion source, an analyzer and a detector (Fig. 1). In the ion source, the analyte is ionized using various methods. The ions are usually extracted from the ion source using an electric field and fed to the analyzer. Here, the ions are now separated according to their mass-to-charge ratio, which can be achieved using very different technical variants. Finally, the detector is used to record the previously sorted ions, with a wide variety of detector types and modes of operation [5].

Diversity in Variation – The great Strength of Mass Spectrometry

As already mentioned, there is a wealth of different MS variants. Not only do you have the choice between different types of ion sources, analyzers and detectors - it is also possible to couple mass spectrometers with chromatography methods in order to sequentially obtain the different mass spectra of the individual fractions [4]. The combination with gas chromatography (GC-MS) or liquid chromatography (LC-MS) is particularly popular. Here, the advantages of two analytical devices are combined, namely the separation capacity of the gas or liquid chromatograph with the sensitivity and specificity of the mass spectrometer [6].

MassSpec_Figure2

Figure 2: Procedure for tandem mass spectrometry (MS/MS). The sample is first ionized by ESI or MALDI and the ions are selected in the first analyzer according to their mass-to-charge ratio (m/z). The selected ions are then further fragmented by collision-induced dissociation (CID) to obtain smaller and clearly identifiable fragments. These are captured and analyzed in a second analyzer [9].

However, coupling to chromatography methods is not the only common practice - mass spectrometry is also often coupled to itself! Tandem mass spectrometry, or MS/MS for short, is actually one of the most common advances of conventional mass spectrometry (Fig. 2). Two analyzers are combined with an intermediate reaction in order to improve the selectivity and sensitivity of the quantification method. In the first analyzer, the ions are scanned and selected according to their m/z ratio. Electrospray ionization (ESI) or matrix-assisted laser desorption/ionization (MALDI) is often used for ionization [7]. After selection in the first analyzer, the ambiguously identified ions are further fragmented in a collision-induced dissociation (CID) chamber. These lighter fragment ions then enter the second analyzer, which analyzes them according to m/z and provides precise information about the structure of the molecule by detecting all fragments [8].

All about Patterns: What does a Mass Spectrum tell us?

Mass spectrometry is a rather complex technology - some people may wonder what it's all for. Couldn't you just use an immunoassay instead? It would definitely be less time-consuming and much cheaper. Nevertheless, MS outperforms an immunoassay in many respects. Imagine the following scenario: A man is involved in a traffic accident with his car in which a pedestrian is seriously injured. It is suspected that the man was under the influence of heroin. To verify this assumption, a blood sample is taken from the driver for analysis. You now reach for the immunoassay - but what does a positive test result tell you? The assay can only identify the drug group (opiates), but not the specific compound. This is not enough to prove heroin abuse and therefore a criminal offense, as the man could have simply taken opiate-containing drugs.

In contrast, an MS analysis allows you to clearly identify and measure each individual compound: The detection of 6-acetylmorphine, a metabolic product of heroin, reveals the drug abuse and thus the criminal offense committed. The information is obtained from the result of the MS measurement, the so-called mass spectrum. A mass spectrum is all about patterns, and each of these specific patterns is unique to a particular compound (Fig. 3). It provides information about the mass and structure of the molecule. A mass spectrum is represented as two-dimensional information of ion abundance versus m/z, with the peaks indicating the intensity of the associated signals. Normally, the ion with the highest mass in the mass spectrum is the molecular ion, and the corresponding signal is called a molecular ion peak. The other ions are fragment ions formed directly or in multiple stages, so-called primary and secondary fragment ions (Fig. 3) [10].

MassSpec_Figure3

Figure 3: Highly fragmented mass spectrum. The sample was ionized by electron impact ionization (EI) [11].

In order to guarantee the precision and accuracy of an MS analysis, the use of appropriate reference materials, so-called standards, is essential. These standards make it possible to calibrate the measurement results and validate the identification and quantification of analytes. By using high purity and certified standards, it can be ensured that the measurement results are consistent and reproducible. There are different types of standards, including internal standards, which are added to samples to compensate for losses during sample preparation, and external standards, which are used to calibrate the mass spectrometers. Internal standards are usually an isotopically labeled version of the molecule of interest. High-quality standards are therefore an indispensable tool for obtaining reliable and accurate MS data, especially when analyzing complex samples or validating measurement results in research and development.

Accelerated MS Analyses with Cayman Chemical

Our supplier Cayman Chemical supports you in your MS analyses with its high-quality chemicals. In principle, all Cayman biochemicals and forensic articles can be used in a mass spectrometer. Especially noteworthy, however, are the large selection of reference standards and the MaxSpec® product range with ready-to-use standards and analysis kits to optimize your mass spectrometry workflows. The MaxSpec® range meets extremely stringent quality standards and ensures quantitative accuracy and reproducibility [12].

The selection of high-purity MS standards ranges from prostaglandins and eicosanoids to leukotrienes, lipoxins, thromboxanes, fatty acids and fatty acid amides [13].

The advantages of MaxSpec® standards at a glance:

Ready-to-use
Verified concentration
LC-MS identity tested
HPLC purity tested
High stability
Supplied in a deactivated glass ampoule and sealed under argon
Detailed certificate of analysis included

Product Number	Product Name	Size
Cay10007269-10	20-HETE MaxSpec® Standard	10 µg
Cay10007270-100	Arachidonoyl Ethanolamide MaxSpec® Standard	100 µg
Cay10007211-100	Prostaglandin E2 MaxSpec® Standard	100 µg
Cay10007268-1	Arachidonic Acid MaxSpec® Standard	1 mg
Cay26415-1	Eicosapentaenoic Acid MaxSpec® Standard	1 mg
Cay18702-1	SPM D-series MaxSpec® LC-MS Mixture	1 each
Cay19412-1	Lipoxin MaxSpec® LC-MS Mixture	1 each
Cay19101-1	Primary COX and LOX MaxSpec® LC-MS Mixture	1 each

All MaxSpec® Standards and Mixtures from Cayman Chemical

Cayman Chemical also offers MaxSpec® analysis kits as all-in-one solutions to optimize sample and standard preparation for mass spectrometry applications. These kits contain all necessary reagents including a detailed protocol to simplify workflows and improve reproducibility. Cayman's portfolio includes kits for the quantification of lysosomal acid lipase or biotinidase activity in dried blood samples, for the sensitive detection of dienes such as vitamin D or vitamin D metabolites, and for the detection of eicosanoids and lipids by a novel derivatization method [14].

The advantages of MaxSpec® analysis kits at a glance:

Purpose built for mass spectrometry
Streamline sample and standard preparation
Each lot rigorously tested
Consistent performance and reproducibility
Contain all necessary reagents

Product Number	Product Name	Size
Cay601510-100	Dienes Derivatization MaxSpec® Kit	100 Tests
Cay601540-50	Oxysterol Derivatization MaxSpec® Kit	50 Tests
Cay601460-1	Hydrogen Peroxide Ratiometric MaxSpec™ Kit	1 each
Cay24854-1	Lysosomal Acid Lipase Activity MaxSpec® Assay Kit	1 each
Cay710000	AMP+ MaxSpec® Kit	15/50/100 Tests