Analytical derivatization (AD), a subset of functional group analysis, alters the structure of an analyte to a product more suitable for analysis. The reactions impart stability to the product and a ...functionality that enhances sensitivity and specificity to the determinations. By targeting the functional groups for labeling AD adds selectivity to the measurements. Associated with these advantages, however, is the additional step required in sample preparation. The issue of the extra step was resolved by solid phase analytical derivatization (SPAD) which combined the extraction and derivatization step or limited the process to a one-pot reaction in which extraction and derivatization occurred on the solid phase without intermediate isolation of the analyte. Within the broad class of organic acids, SPAD provides conditions that can: derivatize both functionalities; selectively derivatize carboxylic acids in the presence of phenols by reaction at neutral pH which does not ionize phenols; derivatize phenols in the presence of acids by selectively inhibiting derivatization of carboxylic acids at alkaline pH. These reaction characteristics hold whether carboxylic acids are on different compounds or on the same compounds. In the case of carbonyls, SPAD enhances the reaction rate over solution chemistry so that both aldehydes and the usually slower reacting ketones are rapidly extracted/derivatized in one step. The derivatization incorporates chromophores, fluorophores and electrophores for purpose of detection, as well lipophilicity for purpose of extraction. In the case of primary and secondary amines, SPAD functional groups that enhance sensitivity and/or lipophilicity. Initially, SPAD was a batch process but transitioned into a microextraction/derivatization and an automated technique.
•Overview of sample preparation methods.•Overview of analytical derivatizations.•Applications of Solid phase analytical derivatizations in analysis.•The mechanistic aspects of Solid phase analytical derivatizations.
Bromophenols (BPs) are a class of ubiquitous emerging halogenated pollutants. Their 19 congeners are problematically separated and detected. This work described the separation and detection of 19 BP ...congeners by gas chromatography-mass spectrometry (GC-MS). Investigations into the derivatization of bromophenols were carried out using two silylation reagents (N,O-bis(trimethylsilyl)trifluoroacetamide and N-methyl-N-(trimethylsily)trifluoroacetamide), two alkylation reagents (methyl iodide and trimethylsilyldiazomethane) and acetic anhydride prior to GC-MS analysis. Optimal chromatographic separation, sensitivity, and linearity were achieved after BP derivatization using acetic anhydride, featuring the equipment detection limits of 0.39–1.26 pg and correlation coefficients of 0.9948–0.9999 (linear range: 0.5–250 ng mL−1) for all 19 BP congeners. Furthermore, the simultaneous determination of 19 bromophenols and 19 bromoanisoles, common environmental transformation products of BPs, is also demonstrated. The improved analytical performance on GC-MS after derivatization would benefit investigations on the environmental origins, behaviors and fates of BPs and their environmental metabolites.
Display omitted
•Five derivatization reagents were compared for bromophenol analysis.•Acetylation achieved the best selectivity, linearity, and sensitivity.•All bromophenols and bromanisoles can be resolved on GC-MS using acetylation.
Haloacetic acids (HAAs), which are the second largest group of halogenated disinfection byproducts, raise great analytical challenges because of their hydrophilicity, non-volatility, and acidity. To ...determine HAAs in drinking water, many pretreatment methods (such as extraction and derivatization) have been proposed since 2000. These methods vary significantly in principles and performance, each carrying inherent analytical errors. This review critically compared typical pretreatment, separation, and detection techniques in terms of advantages and disadvantages, aiming to enable an in-depth and comprehensive understanding of HAAs analysis and help researchers meet analytical requirements. Accordingly, we also identified several analytical error sources less considered before, which may alert later method developers. Finally, we proposed several research prospects, such as analyzing trace amounts of multiple HAAs in their native chemical form, especially for iodoacetic acids at ng/L levels, under mild conditions, e.g., free of reagents, ambient temperature, and neutral pH conditions.
•HAAs analysis is challenging since they are hydrophilic, non-volatile, and ionic.•Novel GC, LC, IC, and CE methods are developed for HAAs analysis since 2000.•Pretreatment, separation, and detection techniques are necessary for HAAs analysis.•Proper use of each method should first have a good understanding of error sources.•Next-generation HAAs analytical methods should be handy, cheap, and sensitive.
The feasibility of on‐capillary derivatization of saccharides by aromatic amine‐based fluorescent labeling agents was tested. To avoid the problematic evolution of gaseous hydrogen cyanide, the ...Schiff base reduction by sodium cyanoborohydride, as the second step of the standard reductive amination protocol, was omitted. Glucose was used as a model analyte and 7‐amino‐1,3‐naphthalenedisulfonic acid as the labeling agent. Our experiments showed that the direct reaction of the saccharide with the labeling agent in 2.5‐M acetic acid yields a labeled product that is sufficiently stable to be separated from the labeling agent in 20‐mM phosphate buffer, pH 3.5, and detected using UV detection. The glucose and label zones were introduced separately into the capillary and mixed using a negative voltage. Mixing voltage, its duration, the concentration of acetic acid in the reaction zone, and the waiting time between mixing and separation were optimized. To show the applicability of the procedure to a broader range of analytes, a mixture of different types of saccharides, that is, xylose (pentose), fucose (hexose), glucose (hexose), N‐acetylglucosamine (N‐acetylaminosaccharide), and lactose (disaccharide), was subjected to derivatization and analysis under the optimal conditions. The linearity and repeatability of the process were evaluated as critical parameters for its analytical applications. Six‐point calibration dependences in the 1–50 mM range showed excellent determination coefficients of 0.9992 or higher for all five saccharides tested. The repeatability of the labeled saccharide peak areas was between 2.2% and 4.3%.
Carboxyl-containing compounds (CCCs) are indispensable for human body and related to the management of numerous diseases. However, it is still rather challenging to determine them in food both ...qualitatively and quantitatively because of their similar or diverse structures and the difference of polarity, concentration, ionization efficiency, and separation ability. Fortunately, derivatization-LC-MS can overcome such limitation and has been playing a more important role in food chemistry for recent decades. There have been no systematic reviews about CCCs together in food, thus CCCs were grouped and discussed comprehensively in terms of structures, biological functions, and abundant food sources. In addition, how derivatization LC-MS technique can provide increased detection sensitivity, improved chromatographic separation, improved identification capacity, and accurate quantitative capacity are summarized. Herein we aim to emphasize various functional CCCs in food and identify derivatization LC-MS as a powerful analytical tool to analyze food samples.
•Major kinds of CCCs in diverse food were summarized.•Many CCCs in food were discovered through derivatization assisted LC-MS.•Powerful derivatization reagents to determine CCCs using LC-MS are outlined.•Derivatization LC-MS technique is a powerful tool in analyzing CCCs in food.
•An in suit derivatization-extraction integrated system was established.•Combined with isotope labelling derivatization, the accuracy was enhanced.•Amine/phenol submetabolome of human plasma was ...profiled.•Potential diagnosis biomarkers in lung cancer plasma were screened out.
Amine/phenol submetabolome has shown critical role in clinical cancer screening and therapy. In suit derivatization has widely applied in the analysis of amine/phenol submetabolome by LC/MS for simplifying the pretreatment procedures, improving the separation and sensitivity. However, the complexity of biological matrix and trace amount of metabolites in plasma that lead to the limited detection coverage, poor repeatability and low extraction efficiency are still issues for in suit derivatization. Herein, we proposed an isotope labelled in suit derivatization-extraction integrated system for targeted analysis of all the metabolites in amine/phenol submetabolome with high efficiency and repeatability by LC-MS. The processes of in suit derivatization, alkalization and extraction were performed simultaneously in the nanopores highly dispersed between the carbon nanofibers based on the nanoconfinement effect. Isotope labelling derivatization (ILD) reagents benzoyl chloride (BzCl) and BzCl-d5 were used to enhance the accuracy of identification and relative quantification. The detection sensitivity was increased up to 5.91-fold and detection coverage was enhanced more than 25% compared with conventional derivatization method. After systematical validation, the established methodology was applied to profile the amine/phenol submetabolome of human plasma and 1498 metabolites were screened out, among which, 1004 (67.02%) were positively or putatively identified. Furthermore, 106 amine/phenol metabolites exhibited significant difference between lung cancer patients and healthy controls by using multiple data processing methods. Taken together, the isotope labelled in suit derivatization-extraction integrated system was a useful approach for the analysis of amine/phenol submetabolome in plasma with broad metabolome coverage, simple pretreatment steps, high detection sensitivity and accuracy, and could be a potential tool for clinical biomarker discovery of disease.
Chemical derivatization-based liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) technique is an effective analytical tool for trace small-molecular weight compounds analysis ...present in complex samples. Chemical derivatization technique can improve the detection sensitivity, selectivity, chromatographic separation and identification capability of LC-ESI-MS analysis. In this review, we summarized the progress of chemical derivatization-assisted LC-MS methods in the period of 2014–2018, according to the functional groups of analytes, such as carboxyls, amines, carbonyls, thiols, hydroxyls, phosphates, modified nucleic acids, conjugated dienes and carbon-carbon double bonds. We mainly focused on the reaction principles of representative derivatization reagents with some application cases highlighting the impact of chemical derivatization-assisted LC-MS technique, which would be helpful for the designing and synthesis of new derivatization reagents for the analysis of small-molecular weight compounds in complex samples.
•We provide a comprehensive review of derivatization-based LC-MS in the period from 2014 to 2018.•We summarize the principles and properties of representative derivatization reagents.•We discuss the typical application cases of derivatization to highlight their impact.•We describe the advantages and prospects of derivatization based LC-MS.
•We provide a comprehensive review of derivatization-based LC-MS studies.•We discuss the selection strategy for derivatization reagents.•We summarize the reaction mechanisms of representative ...derivatization reagents.•We describe the advancement of derivatization methods with advantages and prospects.•We summarize applications of derivatization in various research fields.
Liquid chromatography-mass spectrometry (LC-MS) is one of the most prominent analytical techniques, due to its inherent selectivity and sensitivity. In LC-MS, chemical derivatizations are frequently used to enhance the MS ionization efficiency and selectivity, to facilitate structure elucidation, and to improve the chromatographic separation. In this review, we present an overview of derivatization-based LC-MS analysis. We summarize the reaction mechanisms of representative derivatization reagents and the selection strategy to guide and to stimulate future studies. Furthermore, we emphasize applications of derivatization in peptide and protein analysis, metabolite analysis, environmental analysis, pharmaceutical analysis, food-safety evaluation and MS imaging.
Saccharides are a sort of ubiquitous and vital molecules within the whole life. However, the application of saccharides analysis with matrix-assisted laser desorption/ionization mass spectrometry ...(MALDI-MS) is restricted by their low ionization efficiency and the instability of the sialic acid fraction. Derivatization strategy based on nonreductive amination provides a good solution, however, this is often time consuming and may result in sample loss due to removal of excessive derivatization reagents. Herein, hydralazine (HZN) was utilized as a reactive matrix for labeling reducing saccharides directly on MALDI target which eliminated tedious sample preparation and avoided sample loss. After optimization, effective and reproducible on-MALDI-target derivatization of neutral and acidic saccharides was achieved in both positive and negative modes. Compared with 2,5-dihydroxybenzoic acid (DHB) and 9-aminoacridine (9-AA), HZN improved the detection sensitivity of reducing saccharides and provided more abundant fragment ions in MS/MS analysis. Moreover, 26 kinds of neutral glycans and 5 kinds of sialic glycans were identified from ovalbumin (OVA) and bovine fetuin, respectively. Combined with the statistical models, this strategy could be used to distinguish and predict samples of 6 brands of beer, and discriminate 2 kinds of beer fermentation modes. In addition, HZN was applied for quantitative analysis of glucose in urine samples, and the obtained urine glucose concentrations of diabetic patients were consistent with the clinical test results, showing the potential of qualitative and quantitative analysis of reducing saccharides in complex samples.
Hydralazine (HZN) was utilized as a reactive matrix for labeling reducing saccharides directly on MALDI target which avoided tedious sample preparation and sample loss. After optimization, effective and reproducible on-MALDI-target derivatization of neutral and acidic saccharides was achieved in both ion modes. Display omitted
