Matrix-assisted Laser Desorption/ionization Mass Spectra Research Articles

Effect of Counterions on the Soft Ionization Mass Spectra of Analytes with Multiple Permanent Charges.

Multiply permanently charged analytes (MPCAs) are of great interest for various applications. MPCA soft ionization mass spectra (MS) strongly depend on the counterions of MPCA. We have studied thoroughly this effect to expand the use of MS in MPCA characterization. To this end, β-cyclodextrin-based MPCAs with 7 (MIM7NBCD) and 14 (MIM14BCD) quaternary ammonium charges with a series of monovalent counterions were prepared and their MS were measured using two of the most popular soft ionization techniques, electrospray ionization (ESI) and matrix-assisted laser desorption ionization (MALDI). MALDI MS of both analytes were well resolved, with signals assignable to the analytes only with the two least basic tested counterions (ClO4- and TfO-). Similarly, analyte-assignable signals were observed in ESI MS of MIM14BCD only with ClO4- and TfO-. The situation was opposite with ESI MS of MIM7NBCD where assignable signals were observed with Cl- but not with TfO-. Thus, to get high-quality MS, binding between the MPCA permanent charges and the counterions must be of the optimal effective strength, given also by the number of analyte permanent charges as shown by the simple combinatorial model of binding. Of practical interest is the observation that unsuitable counterions can be replaced in situ by an excess of corresponding acid. The findings form a coherent framework for interpreting and improving MPCA mass spectra.

Mass spectrometry study of ascorbyl palmitate as an agent for nanosomes formation

Background. Study of properties and intermolecular interactions of biologically active compounds which can be used for the purposes of transmembrane drugs delivery is a topical task of modern molecular biophysics. Ascorbyl Palmitate (AP) as a fat-soluble form of vitamin C has recently attracted attention as a promising agent for formation of nanosomes for the “fat insoluble” drug molecules transfer through membranes. However, AP is not sufficiently characterized by up-to-date soft ionization mass spectrometric techniques. Objectives. The aim of the present work is to characterize AP and its intermolecular interactions by a number of mass spectrometric techniques: Electrospray Ionization (ESI), Laser Desorption/Ionization (LDI) and Matrix-Assisted Laser Desorption/Ionization (MALDI). The comparison of these techniques applicability to the study of AP intermolecular interactions as a drug delivery assisting agent is scheduled. Methods. ESI mass spectra are obtained with triple quadrupole Micromass Quattro mass spectrometer. LDI and MALDI experiments are performed by Autoflex II mass spectrometer. Results. In the ESI experiments in the positive ion mode abundant peaks of protonated and cationized AP molecules as well as the peaks of AP clusters nAP•H+ and nAP•Na+ (n=2÷4) are revealed in the mass spectra. This result testifies to the formation of stable noncovalent complexes of the AP molecules in the polar media and confirms the AP ability of formation nanosomes for drug delivery. Analysis of LDI and MALDI mass spectra of AP in positive and negative ion modes shows that in the presence of molecular ions of AP, the peaks of AP dimers or larger AP clusters are not recorded. The ESI probing of the model system containing AP and dipalmitoylphosphatidylcholine (DPPC) reveals stable AP•DPPC•H+ complex which models the AP intermolecular interactions with the phospholipid components of biomembranes and/or liposomes under AP functioning as a drug delivery assisting agent. Conclusions. The current study demonstrates the applicability of all tested mass spectrometric techniques for AP identification in solutions and solid phase, while for the purpose of examining of the AP noncovalent complexes formation and study of AP interactions with biomolecules the ESI is defined as the most effective technique.

The Use of Polydialkylsiloxanes/Triflic Acid as Derivatization Agents in the Analysis of Sulfur-Containing Aromatics by “Soft”-Ionization Mass Spectrometry

Polycyclic aromatic sulfur-containing compounds are widely distributed in oil, especially in its low-volatile and heavy fractions (resins, asphaltenes), and this dictates the need for their determination when reliable methods for sulfur removing, cleaning and processing oil are developed. In these cases, "soft" ionization mass spectrometry methods, based on electrospray ionization (ESI) and matrix-assisted laser desorption/ionization (MALDI), are particularly effective. However, aromatic sulfur-containing compounds have low polarity and cannot be readily ionized by these methods. To overcome the problem, their preliminary conversion into sulfonium salts by the action of alkyl iodides and a silver-containing agent is widely used. In the process of developing more economical derivatization methods, we found a rather unexpected possibility of implementing S-alkylation of organic sulfides with commercial polydialkylsiloxanes (alkyl = CH3 or C2H5) in the presence of triflic acid (CF3SO3H) as a superacid co-alkylating agent. For homologous dibenzothiophenes as a typical model representative of petroleum sulfur-containing aromatic compounds, ESI and MALDI mass spectra exhibited the signals of corresponding S-alkylsulfonium salts with a high signal-to-noise ratio. A rational mechanism for the described chemical transformation is proposed, including the indispensable activation by triflic acid and the cleavage of the Si-C bond. Specific collision-induced dissociation of corresponding S-alkylated sulfonium cations is considered. The applicability of the derivatization approach to the analysis of petroleum products by high-resolution mass spectrometry is demonstrated.

New suitable deprotonating matrices for the analysis of carboxylic acids and some acidic compounds by matrix-assisted laser desorption/ionization mass spectrometry in negative ion mode.

Direct non-derivatization analysis of organic acids and acidic compounds by matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) in positive ion mode is not always possible due to the low ionization efficiency of analytes. Some new efficient deprotonating matrices were suggested that allowed the production of negative ions from acidic compounds during MALDI-MS experiments. Various tested carboxyl-containing compounds as well as compounds with acidic properties were mixed with the suggested deprotonating matrices [4-dimethylaminobenzaldehyde (DMABA), N,N-dimethylamino-p-phenylenediamine or 3-aminoquinoline] and applied on a standard MALDI target followed by recording MALDI mass spectra in negative ion mode. All the tested acidic compounds mixed with the suggested deprotonating matrices produced abundant [M - H]- ions under MALDI conditions. DMABA produced the strongest signals reflecting greater sensitivity of analysis. The suggested deprotonating matrices are commercially available compounds and are good alternatives to well-known matrices of this kind and, in particular, the often used 9-aminoacridine. DMABA is the best of the tested potential matrices and is suitable for the detection of low molecular weight carboxyl-containing compounds, substituted phenols, and mixtures of naphthenic acids by (-)MALDI-MS.

Single Atom Alloy Preparation and Applications in Heterogeneous Catalysis

There have been remarkable progresses in manipulating heterogeneous catalysts' nanostructures in the past decade. The concept of single atom alloy (SAA) was firstly proposed in 2012 when researchers successfully stabilized single Pd atoms on the Cu(111) surface. However, earlier work in 2009, which focused on replacing one Au atom with a Pd atom in thiolate protected Au25 nanoclusters, could also be considered as the pioneer work of single atom alloy. Both kinds of single atom alloys exhibited the potential of maximum utilization of scarce elements and attractive catalytic performances. The well‐defined structures of SAA catalysts make accurate modeling possible, which further realizes the rational design of single atom alloy catalysts. In this review, we summarize the research trajectory of single atom alloys as well as recent achievements in this field. We also introduce several commonly adopted characterization methods for SAA catalysts such as scanning tunneling microscopy (STM), temperature programmed reaction (TPR), extended X‐ray absorption fine structure (EXAFS) spectra, matrix assisted laser desorption/ionization mass spectrum (MALDI‐MS) and differential pulse voltammetry (DPV). Through discussing recent progresses in SAA catalysts, we propose that future researches in this filed should be focused on exploring new kinds of metal nanocrystals and controlling the nanostructure of SAA even more precisely.

Silylation with the Generation of a Fixed Charge for the Analysis of Alcohols by MALDI and SALDI Mass Spectrometry

A new method of the derivatization of alcohols for their analysis by matrix-assisted laser desorption/ionization (MALDI) and surface-assisted laser desorption/ionization (SALDI) is proposed. The approach is based on the silylation of the analytes with bromomethylchlorodimethylsilane in the presence of tertiary amines to yield fixed-charge containing derivatives. The proposed method was tested using aliphatic alcohols, terpenols, and sterols. MALDI and SALDI mass spectra of all derivatives contain intense ion peaks corresponding to their cationic parts.

Ionic liquid matrices for MALDI mass spectrometry of lignin.

The use of matrix-assisted laser desorption/ionization (MALDI) mass spectrometry for the study of lignin is still extremely limited due to its low ionization efficiency. We have developed an approach for obtaining high-intensity MALDI mass spectra of lignin, based on the use of ionic liquids as matrices. Thirty-two ionic liquids consisting of large nitrogen-containing cations and anions of aromatic acids, traditionally used as crystalline matrices, were tested. It was established that ionic liquids based on N,N-diisopropyl-N-ethylammonium, N-isopropyl-N-methyl-N-tert-butylammonium, 3-aminoquinolinium, pyridinium, and 1-methylimidazolium cations and anions of ferulic, α-cyanohydroxycinnamic, and 2,5-dihydroxybenzoic acids as MALDI matrices provided high efficiency of lignin desorption/ionization with generation of singly charged protonated molecules of its oligomers. The use of such matrices in combination with the MALDI quadrupole ion trap-time-of-flight technique allows high-intensity mass spectra of lignin to be obtained without interferences from the matrix in the molecular weight range up to 3kDa, adequately reflecting the molecular mass characteristics of lignin preparations. Using ionic liquid matrices, MS2 and MS3 MALDI mass spectra of lignins for various precursor ions were first obtained, including in the region of large (> 2kDa) molecular weights. Differences in tandem mass spectra of coniferous and deciduous lignins, reflecting the structural features of corresponding oligomers were demonstrated. Graphical abstract ᅟ.

Deconvolution in mass spectrometry based proteomics.

Mass spectrometry (MS) has played a vital role across a broad range of fields and applications in proteomics. The development of high-resolution MS has significantly advanced biology in areas such as protein structure, function, post-translational modification and global protein dynamics. The two most widely used MS ionization techniques in proteomics are electrospray ionization (ESI) and matrix-assisted laser desorption/ionization (MALDI). ESI typically yields multiple charge values for each molecular mass and an isotopic cluster for each nominal mass-to-charge (m/z) value. Although MALDI mass spectra typically contain only singly charged ions, overlapping isotope patterns can be problematic for accurate mass measurement. To overcome these challenges of overlapping isotope patterns associated with complex samples in MS-based proteomics research, deconvolution strategies are being used. This manuscript describes a wide variety of deconvolution strategies, including de-isotoping and de-charging processes, deconvolution of co-eluting isomers or peptides with different sequences in data-dependent acquisition (DDA) and data-independent acquisition (DIA) modes, and data analysis in intact protein mass determination, ion mobility MS, native MS, and hydrogen/deuterium exchange MS. It concludes with a discussion of future prospects in the development of bioinformatics and potential new applications in proteomics.

Lactate-Induced Glucose Output Is Unchanged by Metformin at a Therapeutic Concentration - A Mass Spectrometry Imaging Study of the Perfused Rat Liver.

Metformin is the first line drug for type 2 diabetes but its molecular mechanisms remain unclear. Here, we have studied the acute effect of a therapeutically relevant intrahepatic concentration of metformin on glucose production from lactate. We selected the perfused rat liver as experimental system since it enables the complete control of drug dosage. We used MALDI (matrix-assisted laser desorption/ionization) mass spectrometry imaging to estimate the concentration of metformin in the livers and we measured the concentration of glucose in the effluent medium under basal conditions and following lactate addition. MALDI mass spectra of thin-sections of freeze-clamped rat liver perfused with metformin showed a peak at 130.16 m/z which was unambiguously assigned to metformin. The mass spectrometric detection limit was at a tissue concentration of about 250 nM, and uptake of metformin from the perfusion medium to the liver occurred with a Km of 0.44 mM. Metformin was evenly distributed in the liver irrespective of its concentration in the perfusion medium and the duration of a perfusion. At a parenchymal concentration of 30 μM, metformin did not induce any significant suppression of the basal or lactate-induced glucose release from the liver. These results show that matrix-assisted laser desorption/ionization mass spectrometry imaging can be applied to estimate the tissue concentration and distribution of metformin in a therapeutically relevant micromolar concentration range. Our findings challenge the view that metformin causes an inhibition of glucose release from the liver by an acute inhibition of mitochondrial glycerol 3-phosphate dehydrogenase (EC 1.1.5.3).

Binding of Cu+ and Cu2+ with peptides: Peptides = oxytocin, Arg8‐vasopressin, bradykinin, angiotensin‐I, substance‐P, somatostatin, and neurotensin

The intrinsic binding ability of 7 natural peptides (oxytocin, arg8 -vasopressin, bradykinin, angiotensin-I, substance-P, somatostatin, and neurotensin) with copper in 2 different oxidation states (CuI/II ) derived from different Cu+/2+ precursor sources have been investigated for their charge-dependent binding characteristics. The peptide-CuI/II complexes, [M-(n-1)H+nCuI ] and [M-(2n-1)H+nCuII ], are prepared/generated by the reaction of peptides with CuI solution/Cu-target and CuSO4 solution and are analyzed by using matrix-assisted laser desorption/ionization (MALDI) time-of-flight mass spectrometry. The MALDI mass spectra of both [M-(n-1)H+nCuI ] and [M-(2n-1)H+nCuII ] complexes show no mass shift due to the loss of ─H atoms in the main chain ─NH of these peptides by Cu+ and Cu2+ deprotonation. The measured m/z value indicates the reduction of CuI/II oxidation state into Cu0 during MALDI processes. The number and relative abundance of Cu+ bound to the peptides are greater compared with the Cu2+ bound peptides. Oxytocin, arg8 -vasopressin, bradykinin, substance-P, and somatostatin show the binding of 5Cu+ , and angiotensin-I and neurotensin show the binding of 7Cu+ from both CuI and Cu targets, while bradykinin shows the binding of 2Cu2+ , oxytocin, arg8 -vasopressin, angiotensin-I, and substance-P; somatostatin shows the binding of 3Cu2+ ; and neurotensin shows 4Cu2+ binding. The binding of more Cu+ with these small peptides signifies that the bonding characteristics of both Cu+ and Cu2+ are different. The amino acid residues responsible for the binding of both Cu+ and Cu2+ in these peptides have been identified based on the density functional theory computed binding energy values of Cu+ and the fragment transformation method predicted binding preference of Cu2+ for individual amino acids.

Tryptamine: a Reactive Matrix for MALDI Mass Spectrometry

A possibility of using tryptamine as a reactive matrix for the analysis of non-polar carbonyl compounds by matrix-assisted laser desorption/ionization (MALDI) mass spectrometry has been shown. Presence of a terminal primary amine group in the tryptamine molecule predetermines the formation of Schiff bases from aliphatic and alicyclic carbonyl compounds. No additional matrix compounds are necessary to register MALDI mass spectra, because the excess of the derivatization agent plays the role of a matrix. MALDI mass spectra demonstrate high efficiency of desorption/ionization of the derivatives. To discover reactive matrices, a set of aromatic primary amines (mainly substituted anilines) has been tested, but they have not demonstrated matrix properties.

Oxidative radical driven cleavage of peptide backbone caused by matrix-assisted laser desorption/ionization-in-source decay with low matrix-to-peptide molar ratios

The influence of matrix-to-analyte molar ratio (M/A) on the formation of in-source decay (ISD) fragment ions was examined by matrix-assisted laser desorption/ionization (MALDI) of peptides with the hydrogen-donating matrix 5-amino-1-naphthol (5,1-ANL). MALDI-ISD performed at a low M/A of 6.3:1 resulted in unexpected backbone cleavages that formed (a+16) and y-ions, while ISD spectra at M/A of 630:1 gave the usual fragments of c-, z’-, z-ANL and w-ions. Although the (a+16) and y-ions observed at lower M/A values could not be rationalized by conventional ISD reactions, they were in agreement with the radiolytic products caused by the oxidation of peptides with hydroxyl radical HO. MALDI mass spectra obtained at low M/A showed oxidized analyte ions [M+nO]+ (n=1–4). In addition, the spectra acquired in the low mass range showed peaks corresponding to H±, H3O±, H2O+ (or NH4+), HO−, O2− and HO2−. These results suggest that MALDI-ISD experiments performed at lower M/A values can generate active radical species such as HO, H and HO2, which leads to the oxidative radical driven cleavage of peptides.

Direct MALDI‐MS analysis of the disulfide bonds in peptide using thiosalicylic acid as a reactive matrix

The ability of a thiol-containing molecule, thiosalicylic acid (TSA), to function as a reactive matrix for matrix-assisted laser desorption/ionization (MALDI) mass spectrometry analysis of peptides has been investigated. Although TSA has reducing characteristics, the use of TSA did not cause a reduction-induced MALDI in-source decay, probably because of the weak interactions between the thiol group in TSA and the carboxyl oxygen in the peptide. In contrast, when peptides containing disulfide bonds were analyzed by MALDI with TSA as the matrix, the disulfide bond was partially cleaved owing to the reaction with TSA, producing TSA-adducted peptides. The reaction between the disulfide bond and TSA was suggested to be occurred in solution. The comparison of the MALDI mass spectra obtained using conventional matrix and TSA allows us to count the number of disulfide bonds in the peptides. Copyright © 2017 John Wiley & Sons, Ltd.

High-resolution Kendrick Mass Defect Analysis of Poly(ethylene oxide)-based Non-ionic Surfactants and Their Degradation Products.

Matrix assisted laser desorption ionization (MALDI) high-resolution mass spectrometry (HRMS) and the recently introduced high-resolution Kendrick mass defect (HRKMD) analysis are combined to thoroughly characterize non-ionic surfactants made of a poly(ethylene oxide) (PEO) core capped by esters of fatty acids. A PEO monostearate surfactant is first analyzed as a proof of principle of the HRKMD analysis conducted with a fraction of EO as the base unit (EO/X with X being an integer) in lieu of EO for a regular KMD analysis. Data visualization is greatly enhanced and the distributions detected in the MALDI mass spectrum are assigned to a pristine (H, OH)-PEO as well as mono- and di-esterified PEO chains with palmitate and stearate end-groups in HRKMD plots computed with EO/45. The MALDI-HRMS/HRKMD analysis is then successfully applied to the more complex case of ethoxylated hydrogenated castor oil (EHCO) found to contain a large number of hydrogenated ricinoleate moieties (up to 14) in its HRKMD plot computed with EO/43, departing from the expected triglyceride structure. The exhaustiveness of the MALDI-HRMS/HRKMD strategy is validated by comparing the so-obtained fingerprints with results from alternative techniques (electrospray ionization MS, size exclusion and liquid adsorption chromatography, ion mobility spectrometry). Finally, aged non-ionic surfactants formed upon hydrolytic degradation are analyzed by MALDI-HRMS/HRKMD to easily assign the degradation products and infer the associated degradation routes. In addition to the hydrolysis of the ester groups observed for EHCO, chain scissions and new polar end-groups are observed in the HRKMD plot of PEO monostearate arising from a competitive oxidative ageing.

A simple and easy approach to the derivatization of alcohols for study by soft ionization mass spectrometry methods

A simple and convenient method for the derivatization of alcohols for their subsequent analysis by matrix-assisted laser desorption/ionization (MALDI) mass spectrometry has been proposed. The method includes the acylation of alcohols by bromoacetyl chloride followed by treatment with a base (triethylamine in this work). If amine is used as a base, an excessive amount of it in the reaction mixture immediately reacts with bromoacetate and the process in fact consists of one stage. MALDI mass spectra of the formed quaternary salts recorded in the presence of non-acid matrices or using a target with a nanostructured surface demonstrated only peaks for cationic parts of the derivatives. Using a mixture of aliphatic primary alcohols from C2 to C18, it has been shown that the derivatization reaction proceeds completely and MALDI mass spectra can be used not only for the determination of their molecular masses, but also for their quantitative analysis and profiling.

Study of the primary specificity of proteases by statistical analysis of MALDI mass spectra of proteolysis products

Experimental verification for studying of proteolytic enzymes' primary specificity by statistical analysis of MALDI (matrix-assisted laser desorption/ionization) mass spectra of products obtained by protein substrates proteolysis was done by the use of proteinases with known substrate specificity (trypsin and glutamylendopeptidase). Proposed technique not requires direct determination of proteolysis products amino acid sequences, reliably establishes proteinases with anarrow substrate specificity and shows a relative tolerance for the presence in MALDI mass-spectra peaks of contaminants. It was shown that the pseudo-positive results exception requires the use of protein substrates series with the following averaging received statistical data.

Variable Electrospray Ionization and Matrix-Assisted Laser Desorption/ Ionization Mass Spectra of the Bisquaternary Ammonium Salt Ethonium

Determination of a single “fingerprint” mass spectrum of a biologically active compound, required for compound identification in mixtures and biological materials in such applied tasks as ecological monitoring and biological imaging, may become a nontrivial problem for labile compounds whose mass spectra depend strongly on the applied experimental conditions. In the present communication, qualitatively different mass spectral patterns obtained for the bisquaternary ammonium salt ethonium Cat2+•2Cl– under varied conditions of electrospray ionization and matrixassisted laser desorption/ionization (MALDI) are described and systematized. It is shown that qualitative changes in the electrospray mass spectra of ethonium occur upon a cone voltage increase from 10 V to 100 V, which are caused by the subsequent appearance and destruction of several primary ions: the intact dication Cat2+, the dication-counterion cluster Cat2+•Cl– and[Cat ‑ H]+ and [Cat ‑ CH3]+ ions. Novel experimental evidence of survival of the gas-phase dication Cat2+ with the shortest possible distance of ca 4 Co between the quaternary nitrogen atoms provided by two CH2 groups and Cat2+ fragmentation with preservation of the doubly charged state of the fragments are revealed under soft electrospray conditions. The interpretation of the MALDI mass spectrum is made taking into account the formation of a salt of the bisquaternary ammonium base and 2,5-dihydroxybenzoic acid, which results in the absence of any chlorine-containing ions in the mass spectra and a fragment ion distribution that is different from that observed under electrospray ionization conditions. The main mass spectral features revealed for ethonium may aid in the identification of other types of bisquaternary ammonium compounds.

Effect of laser intensity on the apparent isotope patterns of heme and peptide ions in MALDI-TOF MS

The apparent isotope patterns of heme ions and tryptically digested peptide ions in matrix-assisted laser desorption/ionization (MALDI)-time-of-flight (TOF) mass spectra (MS) were systematically investigated as a function of laser intensity. Two standard proteins, myoglobin and cytochrome c, were tryptically digested to provide heme b and heme c ions, respectively, along with several peptides. MALDI mass spectra of these materials, co-deposited with one of two matrix materials, 2,5-dihydroxybenzoic acid or α-cyano-4-hydroxycinnamic acid (CHCA), were then generated using various laser intensities. For most peptides, the relative abundance of the second isotopic peak (SIP) to that of the monoisotopic peak was similar to the theoretical relative abundances. Regardless of laser intensity, the experimental SIP abundances of heme ions were consistently higher than the theoretical SIP abundances, which is due to the overlap of isobaric species. A gradual increase in the relative SIP abundance of the heme c ion was observed within a certain laser intensity range when the CHCA matrix was used with higher loadings (80pmol) of tryptically digested cytochrome c, which is likely due to saturation of the MALDI-TOF MS detector.

2,5-Dihydroxybenzoic acid solution in MALDI-MS: ageing and use for mass calibration.

2,5-Dihydroxybenzoic acid (DHB) is one of the most widely used and studied matrix compounds in matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. However, the influence of ageing of the DHB solution on the MALDI mass spectra has not been yet systematically studied. In this work, the possible changes occurring in the acidified acetonitrile/water solution of the MALDI matrix compound DHB during 1-year usage period have been monitored with MALDI-Fourier transform ion cyclotron resonance mass spectrometer (MALDI-FT-ICR-MS) and attenuated total reflectance Fourier transform infrared (ATR-FT-IR) spectroscopy. No significant ageing products have been detected. The ability of the aged DHB solution to act as a MALDI matrix was tested with two materials widely used in art and conservation - bone glue (a proteinaceous material) and shellac resin (a resinous material) - and good results were obtained. A number of peaks in the mass spectra measured from the DHB solution were identified, which can be used for internal calibration of the mass axis.

Simple approach to derivatization of alcohols and phenols for the analysis by matrix(surface)-assisted laser desorption/ionization time-of-flight mass spectrometry.

Direct analysis of hydroxyl-containing compounds by matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) methods is not always possible due to the neutral character of analytes. The suggested fixed-charge derivatization may increase the ionization efficiency for various alcohols and phenols in specific matrix- and surface-activated LDI conditions. Aliphatic and steroid alcohols, as well as chlorophenols, were converted into various ammonioacetyl derivatives, containing a covalently bonded charged group, by reaction with bromoacetyl chloride and amine-type compounds such as triethylamine, pyridine or quinoline. The derivatives are suitable for MALDI-time-of-flight (TOF)MS analysis. Triethylammoniumacetyl, pyridyliumacetyl and quinoliniumacetyl derivatives were prepared from aliphatic alcohols, some sterols and chlorinated phenols in one stage with quantitative yields. The derivatives produced characteristic MALDI and SALDI mass spectra. The suggested derivatization approach for the modification of alcohols is simple and does not require any expensive reagents. The derivatives include a fixed charge and produce intense signals in MALDI (preferentially non-acidic matrices) and matrix-free SALDI (nanostructured target) conditions. Corresponding mass spectra are suitable for the determination of molecular mass and profiling of alcohols.