A novel and sensitive derivatization procedure for the determination of 2-cynaoacetamide in pharmaceutical samples using liquid chromatography with the fluorescence detection was discovered. The method is based on derivatization of 2-cynaoacetamide using 2-hydroxyacetophenone as a new derivatization reagent. The product of derivatization reaction was isolated and characterized using spectroscopic techniques namely LC-MS, NMR and IR. The structure of 2-cyanoacetamide derivative was unambiguously assigned as a 2-amino-4-phenylfuran-3-carboxamide. Two derivatization systems were optimized in terms of reaction temperature, reaction time, pH and concentration of 2-hydroxyacetophenone, and a new pre- and post-derivatization HPLC methods were developed. The separations on HPLC with pre-column derivatization were accomplished using stationary phase based on a XBridge C18 column (100×4.6, 3.5μm) and isocratic elution using the mobile phase acetonitrile - 0.1% formic acid (30:70, v/v). The separations on the HPLC with post-column derivatization were performed on stationary phase on a TSKgel Amide-80 column (150×4.6mm, 3μm). The mobile phase was a mixture of acetonitrile, methanol and 10mM sodium formate buffer at pH=4.5 in ratio 3:2:95 (v/v). Both HPLC methods were fully validated in terms of linearity, sensitivity (limit of detection and limit of quantification), accuracy and precision according to ICH guidelines. The pre-column derivatization method was linear in the range 1.1-2000μg/l with method accuracy≥98.2% and method precision RSD≤4.8%. The post-column derivatization method was linear in the range 12-2000μg/l. Method accuracy≥96.3% and method precision RSD≤3.5%. Proposed new methods were proved to be highly sensitive, simple and rapid, and were successfully applied to the determinations of 2-cynaoacetamide in pregabalin.

• Klíčová slova
• 2-cyanoacetamide, 2-hydroxyacetophenone, Derivatization, Fluorescence detection, Pregabalin,
• MeSH
• acetofenony chemie   MeSH
• hmotnostní spektrometrie MeSH
• indikátory a reagencie * MeSH
• magnetická rezonanční spektroskopie MeSH
• nitrily analýza   MeSH
• pregabalin chemie   MeSH
• spektroskopie infračervená s Fourierovou transformací MeSH
• vysokoúčinná kapalinová chromatografie metody   MeSH
• Publikační typ
• časopisecké články MeSH
• validační studie MeSH
• Názvy látek
• 2-cyanoacetamide MeSH Prohlížeč
• 2'-hydroxyacetophenone MeSH Prohlížeč
• acetofenony MeSH
• indikátory a reagencie * MeSH
• nitrily MeSH
• pregabalin MeSH

Masking derivatization was introduced for the determination of residual solvents in samples containing a volatile reactive matrix component(s). Isobutylboronic acid, used in the last step of Bortezomib synthesis, represents a compound passing to the gas phase and deteriorating a chromatographic column during a headspace analysis. The masking derivatization with 1,8-diaminonaphthalene allowed a simple and straightforward conversion of isobutylboronic acid to a stable nonvolatile derivative and thus prevented gas chromatography column deterioration. The method was successfully validated according to the guidelines of International Committee for Harmonization (Q3C (R6) Guideline for Residual Solvents) and international pharmacopoeias (Ph. Eur., USP) and approved by Teva Czech Industries for routine application.

• Klíčová slova
• derivatization, gas chromatography, isobutylboronic acid, residual solvents, static headspace,
• Publikační typ
• časopisecké články MeSH

Bulk graphitic carbon nitride (CN) was synthetized by heating of melamine at 550 °C, and the exfoliated CN (ExCN) was prepared by heating of CN at 500 °C. Sulfur-doped CN was synthesized by heating of thiourea (S-CN) and by a novel procedure based on the post-synthetic derivatization of CN with methanesulfonyl (CH3SO2-) chloride (Mes-CN and Mes-ExCN). The obtained nanomaterials were investigated by common characterization methods and their photocatalytic activity was tested by means of the decomposition of acetic orange 7 (AO7) under ultraviolet A (UVA) irradiation. The content of sulfur in the modified CN decreased in the sequence of Mes-ExCN > Mes-CN > S-CN. The absorption of light decreased in the opposite manner, but no influence on the band gap energies was observed. The methanesulfonyl (mesyl) groups connected to primary and secondary amine groups were confirmed by high resolution mass spectrometry (HRMS). The photocatalytic activity decreased in the sequence of Mes-ExCN > ExCN > CN ≈ Mes-CN > S-CN. The highest activity of Mes-ExCN and ExCN was explained by the highest amounts of adsorbed Acetic Orange 7 (AO7). In addition, in the case of Mes-ExCN, chloride ions incorporated in the CN lattice enhanced the photocatalytic activity as well.

• Klíčová slova
• derivatization, graphitic carbon nitride, mesyl chloride, photocatalysis, sulfur,
• Publikační typ
• časopisecké články MeSH

The great research interest in the quantification of reactive carbonyl compounds (RCCs), such as methylglyoxal (MGO) in biological and environmental samples, is reflected by the fact that several publications have described specific strategies to perform this task. Thus, many reagents have also been reported for the derivatization of RCCs to effectively detect and quantify the resulting compounds using sensitive techniques such as liquid chromatography coupled with mass spectrometry (LC-MS). However, the choice of the derivatization protocol is not always clear, and a comparative evaluation is not feasible because detection limits from separate reports and determined with different instruments are hardly comparable. Consequently, for a systematic comparison, we tested 21 agents in one experimental setup for derivatization of RCCs prior to LC-MS analysis. This consisted of seven commonly employed reagents and 14 similar reagents, three of which were designed and synthesized by us. All reagents were probed for analytical responsiveness of the derivatives and stability of the reaction mixtures. The results showed that derivatives of 4-methoxyphenylenediamine and 3-methoxyphenylhydrazine-reported here for the first time for derivatization of RCCs-provided a particularly high responsiveness with ESI-MS detection. We applied the protocol to investigate MGO contamination of laboratory water and show successful quantification in a lipoxidation experiment. In summary, our results provide valuable information for scientists in establishing accurate analysis of RCCs.

• Klíčová slova
• carbonyl derivatization, hydroxylamine, lipoxidation, phenylenediamine, phenylhydrazine, water analysis,
• MeSH
• chemické látky znečišťující vodu analýza   MeSH
• chromatografie kapalinová metody   MeSH
• hmotnostní spektrometrie s elektrosprejovou ionizací metody   MeSH
• laboratoře normy   MeSH
• limita detekce MeSH
• pyruvaldehyd analýza   chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• chemické látky znečišťující vodu MeSH
• pyruvaldehyd MeSH

Amino acids are essential compounds for living organisms, and their determination in biological fluids is crucial for the clinical analysis and diagnosis of many diseases. However, the detection of most amino acids is hindered by the lack of a strong chromophore/fluorophore or electrochemically active group in their chemical structures. The highly sensitive determination of amino acids often requires derivatization. Capillary electrophoresis is a separation technique with excellent characteristics for the analysis of amino acids in biological fluids. Moreover, it offers the possibility of precapillary, on-capillary, or postcapillary derivatization. Each derivatization approach has specific demands in terms of the chemistry involved in the derivatization, which is discussed in this review. The family of homocyclic o-dicarboxaldehyde compounds, namely o-phthalaldehyde, naphthalene-2,3-dicarboxaldehyde, and anthracene-2,3-dicarboxaldehyde, are powerful derivatization reagents for the determination of amino acids and related compounds. In the presence of suitable nucleophiles they react with the primary amino group to form both fluorescent and electroactive derivatives. Moreover, the reaction rate enables all of the derivatization approaches mentioned above. This review focuses on articles that deal with using these reagents for the derivatization of amino acids and related compounds for ultraviolet-visible spectrometry, fluorescence, or electrochemical detection. Applications in capillary and microchip electrophoresis are summarized and discussed.

• Klíčová slova
• Derivatization, On-capillary, Postcapillary, Precapillary, o-Dicarboxaldehydes,
• MeSH
• aldehydy chemie   MeSH
• aminokyseliny * analýza   chemie   izolace a purifikace   MeSH
• elektroforéza kapilární metody   MeSH
• elektroforéza mikročipová MeSH
• naftaleny chemie   MeSH
• o-ftalaldehyd chemie   MeSH
• stereoizomerie MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• 2,3-naphthalenedicarboxaldehyde MeSH Prohlížeč
• aldehydy MeSH
• aminokyseliny * MeSH
• naftaleny MeSH
• o-ftalaldehyd MeSH

Many small molecules require derivatization to increase their volatility and to be amenable to gas chromatographic (GC) separation. Derivatization is usually time-consuming, and typical batch-wise procedures increase sample variability. Sequential automation of derivatization via robotic liquid handling enables the overlapping of sample preparation and analysis, maximizing time efficiency and minimizing variability. Herein, a protocol for the fully automated, two-stage derivatization of human blood-based samples in line with GC-[Orbitrap] mass spectrometry (MS)-based metabolomics is described. The protocol delivers a sample-to-sample runtime of 31 min, being suitable for better throughput routine metabolomic analysis. Key features • Direct and rapid methoximation on vial followed by silylation of metabolites in various blood matrices. • Measure ~40 samples per 24 h, identifying > 70 metabolites. • Quantitative reproducibility of routinely measured metabolites with coefficients of variation (CVs) < 30%. • Requires a Thermo ScientificTM TriPlusTM RSH (or comparable) autosampler equipped with incubator/agitator, cooled drawer, and automatic tool change (ATC) station equipped with liquid handling tools. Graphical overview Workflow for profiling metabolites in human blood using automated derivatization.

• Klíčová slova
• Automation, Derivatization, Gas chromatography–mass spectrometry (GC–MS), Metabolite profiling, Thermo ScientificTM TriPlusTM RSH,
• Publikační typ
• časopisecké články MeSH

In-capillary derivatization using fluorescamine as the labeling reagent was proposed to enhance the detectability of adamantine drugs (memantine, amantadine and rimantadine) by spectrophotometric detection. Fluorescamine and the drugs were delivered to the capillary electrophoresis instrument at a ratio of 10:1 by zone injection. The derivatization reaction occurred following the application of voltage (20 kV). The derivatized products, hydrolyzed- fluorescamine and excess fluorescamine were separated in 7 min using 100 mM borate buffer (pH 10.0) containing 0.1% w/v of Brij®-35 and 20% v/v of acetonitrile. Validation data showed good linearity (r2 > 0.98), precision (%RSDs < 3.4), and accuracy (recoveries ranging from 98.0 to 102.0%). The detection and quantitation limits are in the range of 6.0-8.5 and 18-25 μM, respectively. The validation data is comparable to reported methods, however, the current method offers better precision with enhanced sensitivity (up to six times). Applications of the method show percent labeled amounts found in the studied samples within 100.6-109.3%, which complied with the United States Pharmacopeia limit (90.0-110.0%). The method was simple, rapid and, automated, which required no extra instrumentation or skillful operators.

• Klíčová slova
• adamantine, fluorescamine, in-capillary derivatization, memantine, rimantadine,
• MeSH
• adamantan analýza   MeSH
• elektroforéza kapilární MeSH
• fluoreskamin chemie   MeSH
• molekulární struktura MeSH
• spektrofotometrie ultrafialová MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• adamantan MeSH
• fluoreskamin MeSH

Challenges and pitfalls in the application of diethyldithiocarbamate derivatization for LC analysis of cisplatin and oxaliplatin, as well as the suitability of this method for different biological matrices with implications for use in routine practice have been identified. The LC of platinum drugs presents a significant challenge. They are polar compounds with poor retention on reverse phase packings. Cisplatin also exhibits poor absorption in UV and ionization in mass spectrometry. Therefore, we developed and optimized a derivatization approach for the LC analysis of total platinum in plasma, plasma ultrafiltrate, peritoneal fluid, and urine. Derivatization in urine proved to be difficult due to the complexity of the matrix, and extended testing was required. Our results highlight the important issues affecting the efficiency, reliability, and suitability of platinum drug derivatization. Although precolumn derivatization is less selective than its postcolumn counterpart, the application of precolumn derivatization is a simple, rapid, and universal approach for the determination of platinum drugs by HPLC. One of its major advantages is that it allows a more affordable analysis using UV detection without the need for additional high-end instrumentation such as a MS detector.

• Klíčová slova
• derivatization, diethyldithiocarbamate, peritoneal fluid, plasma, platinum drugs,
• MeSH
• cisplatina * MeSH
• dithiokarb MeSH
• platina * MeSH
• reprodukovatelnost výsledků MeSH
• vysokoúčinná kapalinová chromatografie metody   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• cisplatina * MeSH
• dithiokarb MeSH
• platina * MeSH

Histone post-translational modifications (hPTMs) are epigenetic marks that strongly affect numerous processes, including cell cycling and protein interactions. They have been studied by both antibody- and MS-based methods for years, but the analyses are still challenging, mainly because of the diversity of histones and their modifications arising from high contents of reactive amine groups in their amino acid sequences. Here, we introduce use of trimethylacetic anhydride (TMA) as a new reagent for efficient histone derivatization, which is a requirement for bottom-up proteomic hPTM analysis. TMA can derivatize unmodified amine groups of lysine residues and amine groups generated at peptide N-termini by trypsin digestion. The derivatization is facilitated by microwave irradiation, which also reduces incubation times to minutes. We demonstrate that histone derivatization with TMA reliably provides high yields of fully derivatized peptides and thus is an effective alternative to conventional methods. TMA afforded more than 98% and 99% labeling efficiencies for histones H4 and H3, respectively, thereby enabling accurate quantification of peptide forms. Trimethylacetylation substantially improves chromatographic separation of peptide forms, which is essential for direct quantification based on signals extracted from MS1 data. For this purpose, software widely applied by the proteomics community can be used without additional computational development. Thorough comparison with widely applied propionylation highlights the advantages of TMA-based histone derivatization for monitoring hPTMs in biological samples.

• Klíčová slova
• bottom–up proteomics, chemical derivatization, histone post-translational modifications, microwave irradiation, trimethylacetic anhydride,
• MeSH
• acetanhydridy chemie   MeSH
• acetylace MeSH
• chromatografie kapalinová MeSH
• histony chemie   MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• posttranslační úpravy proteinů MeSH
• tandemová hmotnostní spektrometrie MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• acetanhydridy MeSH
• histony MeSH

A completely new voltammetric method has been developed for quantitative determination of food additive Taurine (Tau) in energy drinks. This electroanalytical method is based on voltammetric oxidation of o-phthalaldehyde-ethanthiol derivative of Tau at glassy carbon electrode in 95% methanol containing 0.1 mol L-1 lithium perchlorate. Working conditions necessary for quantitative Tau derivatization reaction and electrochemical detection using square wave voltammetry were optimized. Linear range from 1.0 × 10-5 to 1.0 × 10-4 mol L-1 characterized by coefficient of determination 0.9998, limits of quantification 6.8 × 10-6 mol L-1 and detection 2.1 × 10-6 mol L-1 were obtained at pulse amplitude 50 mV and frequency 80 Hz. Analytical method of calibration curve was used for evaluation of Tau content in several commercially available energy drinks. The procedure was validated using standard reference high performance liquid chromatography (HPLC) method. Both methods showed nearly identical Tau content, around 0.35% (w/w). Besides its reliability to the Tau determination, that is totally comparable to reference method used, present voltammetric approach is more advantageous on the economic and simplicity basis. Finally, developed voltammetric method could find employment in food quality control.

• Klíčová slova
• Derivatization, Food analysis, Glassy carbon electrode, Square wave voltammetry, Taurine, o-phthalaldehyde,
• MeSH
• elektrochemické techniky * MeSH
• energetické nápoje analýza   MeSH
• kalibrace MeSH
• kvalita jídla MeSH
• o-ftalaldehyd chemie   MeSH
• sulfhydrylové sloučeniny chemie   MeSH
• taurin analýza   MeSH
• vysokoúčinná kapalinová chromatografie MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• ethanethiol MeSH Prohlížeč
• o-ftalaldehyd MeSH
• sulfhydrylové sloučeniny MeSH
• taurin MeSH