Derivatization Reagent Research Articles

Profiling of Australian Stingless Bee Honey Using Multivariate Data Analysis of High-Performance Thin-Layer Chromatography Fingerprints

The complex chemical composition of honey presents significant challenges for its analysis with variations influenced by factors such as botanical source, geographical location, bee species, harvest time, and storage conditions. This study aimed to employ high-performance thin-layer chromatography (HPTLC) fingerprinting, coupled with multivariate data analysis, to characterise the chemical profiles of Australian stingless bee honey samples from two distinct bee species, Tetragonula carbonaria and Tetragonula hockingsi. Using a mobile phase composed of toluene:ethyl acetate:formic acid (6:5:1) and two derivatisation reagents, vanillin–sulfuric acid and natural product reagent/PEG, HPTLC fingerprints were developed to reveal characteristic patterns within the samples. Multivariate data analysis was employed to explore the similarities in the fingerprints and identify underlying patterns. The results demonstrated that the chemical profiles were more closely related to harvest time rather than bee species, as samples collected within the same month clustered together. The quality of the clustering results was assessed using silhouette scores. The study highlights the value of combining HPTLC fingerprinting with multivariate data analysis to produce valuable data that can aid in blending strategies and the creation of reference standards for future quality control analyses.

Highly Efficient Compositional and Compound Specific Isotopic Analysis of Volatile Primary Amines and Ammonia in the Murchison Meteorite Using SPME On-Fiber Derivatization: Optimization for Bennu Sample Analyses.

Extraterrestrial amines and ammonia are critical ingredients for the formation of astrobiologically important compounds such as amino acids and nucleobases. However, conventional methods for analyzing the composition and isotopic ratios of volatile amines suffer from lengthy derivatization and purification procedures, high sample mass consumption, and chromatographic interferences from derivatization reagents and non-target compounds. Here we demonstrate a highly efficient method to analyze the composition and compound specific isotopic ratios of C1 to C6 amines as well as ammonia based on solid phase micro-extraction (SPME) on-fiber derivatization. 2,3,4,5,6-pentafluorobenzyl chloroformate (PFBCF) adsorbed on a solid phase SPME fiber is subsequently exposed to the headspace of the water extract of the Murchison meteorite to selectively extract, derivatize and concentrate volatile amines and ammonia. PFBCF does not directly contact the aqueous solution containing other soluble organics. An aliquot of volatile amines and ammonia in the headspace are selectively derivatized on the SPME fiber and subsequently thermally desorbed onto the GC injector for analysis. Only the amounts of amines required for either compositional or isotopic analysis are derivatized and consumed in the process, preserving the bulk fraction of amines and ammonia for other analyses, and the process does not affect other volatile compound classes. Carbon and hydrogen isotopic ratios of amines are obtained by isotopic mass balance. The exceptional selectivity and sensitivity of SPME on-fiber derivatization of volatile amines in carbonaceous chondrite extracts allow minimization of sample consumption. Carbon and hydrogen isotopic values of individual amines in the Murchison meteorite are consistent with their extraterrestrial origin, with a substantial fraction inherited from interstellar molecular clouds. SPME on-fiber derivatization is well suited for analyzing extraterrestrial materials, especially precious asteroid return samples.

Simultaneous determination of naphthalimide-labelled monosaccharides in P. cyrtonema Hua. polysaccharides utilizing the HPLC-UV technique.

4-Amidogen-1,8-naphthalimide (ANA), a novel pre-column derivatization reagent, has been successfully synthesized and utilized for the highly sensitive analysis of monosaccharides. ANA reacts with the reducing carbonyl groups of saccharides, facilitating monosaccharide detection. The resulting monosaccharide derivatives were meticulously investigated using High-Performance Liquid Chromatography (HPLC) coupled with ultraviolet (UV) spectroscopy. The derivatization process was conducted in an environmentally friendly solvent mixture of EtOH and AcOH at a constant temperature of 100 °C for a duration of 4 hours across all monosaccharides. After derivatization, the separated adducts were eluted through a ZORBAX SB-C8 column within a mere 22 minutes at a flow rate of 0.8 mL min-1, with detection occurring at a wavelength of 416 nm. By employing this derivatization technique, the comprehensive analysis of the monosaccharide composition in P. cyrtonema Hua. polysaccharides (PCPs) following strong acid hydrolysis was achieved. The monosaccharide profiles of PCPs predominantly consist of glucose (Glc), galactose (Gal), mannose (Man), xylose (Xyl), and galacturonic acid (GalA), with a molar ratio of Glc : Gal : Man : Xyl : GalA of 20.26 : 12.76 : 24.24 : 41.91 : 0.83. The LOD values for the six sugars ranged from 27.37 to 84.37 μg mL-1. The validated HPLC method, characterized by its exceptional precision and accuracy, has successfully facilitated both rapid qualitative and quantitative determination of PCPs, thereby establishing a robust quality control protocol for P. cyrtonema Hua.

Planar solid phase extraction for chlorinated paraffin analysis - irradiation chamber for standardized derivatization on planar thin-layers.

As an established analytical method, high-performance thin-layer chromatography (HPTLC) offers powerful capabilities. This study focused on its application to analyze chlorinated paraffins (CP) by planar solid phase extraction (pSPE). Based on previous work, an irradiation chamber was developed to investigate the derivatization process on planar thin-layers and ensure a robust and reproducible analysis. A simple-to-handle irradiation chamber was designed to initialize the reaction between CP and the derivatization reagents o-tolidine and tetramethylbenzidine (TMB). It was shown that the complete derivatization reaction is not significantly influenced by the chain length and only depends significantly on the chlorine content of the used standards. Regarding the reaction process, a relation between the chain length and chlorine content was obtained; however, quantitative correlations cannot be found. Furthermore, the derivatization solutions were investigated in terms of stability, different concentrations, and the optimal irradiation time. The method showed robustness regarding signal intensity at irradiation times of 1 to 36 min and amounts of 10-400 ng of the technical reference CP mixture C14-C17 52 % Cl. Its application to CP with chain lengths between C10 and C23 and chlorine content between 40 % and 70 % emphasized the method's versatility.

Quantification of three furfurals in food using a triazine-based hydrazine derivatization reagent by MALDI mass spectrometry

Quantification of three furfurals in food using a triazine-based hydrazine derivatization reagent by MALDI mass spectrometry

Determination of Amino Acids of Novel Food in Food by HPLC Coupled with Pre-Column Derivatization

A method for simultaneous determination of Theanine and γ-aminobutyric acid (GABA), as the novel food of amino acids, which was established using pre-column derivatization and high-performance liquid chromatography (HPLC). 4-Dimethylaminoazobe nzene-4′-sulfonyl chloride (DABS-Cl) is employed as the derivatization reagent with chromophore linked to Theanine and GABA, which lacks chromophore for DAD analysis in its pristine structure. After the detection wavelength was confirmed, the chromatographic and derivatization conditions were also optimized, including the chromatographic column, mobile phases and their gradient, derivatization temperature and time, the additive amount of buffer solution and derivatization reagent. Methodological verification showed that the derivant of Theanine (DABS-Theanine) and derivant of GABA (DABS-GABA) have good linearity in the range of 1–100 μg/mL, with correlation coefficients of 0.9996 and 0.9995, respectively. The recoveries for both amino acids were between 93.95% and 103.90%, with RSDs ranging from 0.99% to 3.93%. The limit of detection (LOD) was 0.6 mg/kg for Theanine and 0.2 mg/kg for GABA. The limit of quantification (LOQ) was 1.7 mg/kg for Theanine and 0.6 mg/kg for GABA. Furthermore, five commercial products containing Theanine or GABA in two matrices (candy and beverage) were analyzed by the proposed method for validation. The average contents of Theanine and GABA were in the range of 307.49–1312.13 mg/kg and 22.98–6744.55 mg/kg, respectively. The developed method features easy sample pretreatment, a simple derivatization system, good separation specificity, good repeatability, accuracy and reliability, and can meet the large-scale determination Theanine and GABA in various food substrates.

Simultaneous Quantitation of Multiple Biological Thiols Using Reactive Ionization and Derivatization with Charged Mass Tags.

The biologically important thiols (cysteine, homocysteine, N-acetyl cysteine, and glutathione) are key species in redox homeostasis, and there is a clinical need to measure them rapidly, accurately, and simultaneously at low levels in complex biofluids. The solution to the challenge presented here is based on a new derivatizing reagent that combines a thiol-selective unit to optimize the chemical transformation and a precharged pyridinium unit chosen to maximize sensitivity in mass spectrometry. Derivatization is performed simultaneously with ionization ("reactive ionization"), and mass spectrometry is used to record and characterize the thiol reaction products. The method is applicable over the concentration range from 1 μM to 10 mM and is demonstrated for 25 blood serum, 1 plasma, and 3 types of tissue samples. The experiment is characterized by limited sample preparation (<4 min) and short analysis time (<1 min). High precision and accuracy (both better than 8%) are validated using independent HPLC-MS analysis. Cystine-cysteine redox homeostasis can be monitored by introducing an additional reduction step, and the accuracy and precision of these results are also validated by HPLC-MS.

Highly sensitive SERS detection of tryptophan based on diazo coupling reaction using two derivatization reagents

In this study, a simple, rapid and sensitive tryptophan (Trp) detection method was proposed, which combined surface enhanced Raman spectroscopy (SERS) with diazo coupling reaction and silver dendritic substrate. Two derivatization reagents, 4-mercaptoaniline (PATP) and 2-fluoro-4-mercaptoaniline (2-F-PATP) were used for derivatization reaction with Trp, which can be controlled by experimental parameters such as derivatization reagent concentration and sodium nitrite concentration. The partial least squares quantitative (PLS) detection model is applied in determining the concentration of Trp. The determination coefficient (R2) of PLS model was 0.9617 based on PATP and 0.9950 on 2-F-PATP. The LOD of the two derivatization methods were as low as 10−11 mol/L. This combined technique has the characteristics of simple operation, high sensitivity and good selectivity, and shows great potential in the detection of Trp in biological media.

Age and sex effects of a validated LC-MS/MS method for the simultaneous quantification of testosterone, allopregnanolone, and its isomers in human serum

Despite the great relevance of the neurosteroid allopregnanolone and related isomers to various health conditions, quantification typically involves immunoassay, which suffers from serious issues with cross-reactivity of closely related molecules. This article describes the development and partial validation of a liquid chromatography coupled with tandem mass spectrometry assay for the simultaneous quantification of allopregnanolone, pregnanolone, isopregnanolone, epi-allopregnanolone, and testosterone in the human serum of healthy males and females aged 5–85 years. 1-amino-4-methylpiperazine (AMP) was used as a derivatisation reagent to enhance the ionisation signal. Linearity was calculated at 0.99 with a lower limit of quantification of 10.08 pg/mL for allopregnanolone, along with a linearity of 0.98 and a lower limit of quantification of 42.32 pg/mL for testosterone. Application of the method showed sex and age effects across the lifespan for both allopregnanolone and testosterone, whereas a comparative immunoassay for allopregnanolone was not able to detect differences in the same samples. Our partial validation of this method should provide a new tool for researchers to discover the role of allopregnanolone and its isomers in human health, and how it compares to testosterone and sex hormones.

Synthesis of 2-methyl-6-methoxy-4-quinolinecarboxylic acid N-hydroxysuccinimide ester (MMQC-OSu) for streamlined and effective HPLC-based fluorescence detection of aliphatic amines in environmental samples

Aliphatic amines are widely distributed in the environment and food sources, posing potential health risks through skin and mucosal irritation. Consequently, their quantitative detection is crucial for assessing environmental health. Despite high reactivity and fluorescence properties of succinimidyl ester-based derivatization reagents, their application in the aliphatic amines detection is hampered by challenges such as limited detection sensitivity and fluorescence interference. We established an innovative synthetic approach to produce a series of succinimidyl esters with the desirable substituents. This advancement enabled the creation of efficient and highly sensitive reagents for the detection of aliphatic amines. Among them, 2-methyl-6-methoxy-4-quinolinecarboxylic acid N-hydroxysuccinimide ester (MMQC-OSu) exhibited the best detection performance. MMQC-OSu reacted with aliphatic amines at 40 °C in pH 8.0 buffer for 20 min, which was subsequently separated in a C18 chromatographic column with the fluorescence detection wavelength of 336/432 nm. This detection approach featured a rapid and mild reaction process, minimal interference from corresponding hydrolysis products, and impressive sensitivity (0.05 nM). These characteristics indicate that MMQC-OSu significantly surpassing commercial aliphatic amines detection reagents. Finally, the detection strategy of MMQC-OSu was successfully applied in environmental sample analysis, with recovery rate of 93 %–108 % and RSDs between 1.4 % and 6.5 %.

Investigating Flavonoids by HPTLC Analysis Using Aluminium Chloride as Derivatization Reagent.

This is the first study to report on high performance thin layer chromatography (HPTLC) generated spectrophotometric data to systematically capture flavonoid compounds using optimized derivatization with either AlCl3 or NaNO2-AlCl3-NaOH as visualisation reagents. While the traditional AlCl3 colorimetric method using UV-Vis analysis provides valuable insights into the presence of flavonoids and allows derivation of the total flavonoid content (TFC) of a sample, HPTLC fingerprints obtained after spraying with AlCl3 or NaNO2-AlCl3-NaOH enable the visualization of the various flavonoids present in a sample based on their respective absorption shifts, thus complementing the traditional TFC assay. In this study, 40 different flavonoids representing different classes (flavonols, flavanolols, flavan-3-ol, flavones, flavanones, and isoflavonoids) were analysed. Upon derivatization with AlCl3 most of the investigated flavonoids recorded bathochromic shifts, yielding characteristic λmax values between 370 and 420 nm, while spraying with NaNO2-AlCl3-NaOH triggered hyperchromic shifts, and thus an increase in absorbance intensity in flavonoids with particular substitution patterns. A few non-flavonoid components with structural similarities to flavonoids (e.g., rosmarinic acid, gallic acid, aspirin, salicylic acid) served as the negative control in this study to determine whether the derivatization reagents allowed exclusive detection of flavonoids. The method was then applied to the analysis of flavonoid containing supplements as well as red clover honey to demonstrate the method's application in the analysis of natural products.

LC enantioseparation of active pharmaceutical ingredients using rationally synthesized CDRs and chiral molecules with high molar absorptivity.

The synthesis of optically active compounds requires determination of ee, er, and enantiomeric purity. The aim of the present paper is to review the synthesis of several chiral derivatizing reagents (CDRs) in a rational manner, which were successful for the separation and isolation of enantiomers of a variety of active pharmaceutical ingredients and other important and useful racemates. Besides, the application of (i) certain enantiomerically pure amines, either directly or by incorporating each of them as chiral auxiliary in difluorodinitrobenzene or cyanuric chloride moieties to construct the CDR, (ii) (S)-ketoprofen and (S)-levofloxacin as chiral platforms, and (iii) a few isothiocyanates, have been suitably included. Attention is drawn to the use of water micellar mobile phase as the "green" RP-HPLC method and the use of simple achiral derivatization with ninhydrin, particularly. Synthesis of CDRs and their application for enantioseparation of racemates and detagging of certain chromophoric reagent components for obtaining native enantiomers are other interesting features included herein. The methods can be easily used to determine and control enantiomeric purity with advantages over a variety of commercial chiral phases. This comprehensive review not only highlights innovative methodologies for enantioseparation but also underscores their practical applications in controlling and ensuring the enantiomeric purity of pharmaceutical compounds.

Enhanced enantioselective separation of racemic menthol via reverse-phase high-performance liquid chromatography: Method development and computational insights for pre-screening

A robust and efficient enantioselective separation of racemic menthol was achieved on a standard C18 column with reverse-phase high-performance liquid chromatography (RP-HPLC) and UV detector. (R)-α-hydroxy-4-methylbenzeneacetic acid was utilized as the pre-column derivatization reagent. The impact of mobile phase composition on diastereomer selectivity was thoroughly investigated, resulting in a high resolution of 2.11 under optimized conditions. The method was rigorously validated for linearity, precision, accuracy, limit of detection (LOD) and limit of quantification (LOQ). Notably, a separation pre-screening mechanism (SPM) and a prediction model was developed based on density functional theory (DFT) studies. This model elucidated the relationship between molecular polarity differences (△MPI) and chromatographic behavior, facilitating the interpretation and prediction of racemic menthol resolution with various chiral derivatization reagents. The present work not only presents an efficient and economical approach for menthol enantiomeric separation, but also offers valuable insights for the innovative design and advancement of chromatographic methodologies for a wide array of chiral enantiomers.

Rapid Determination of Trace Ethylene Glycol and Diethylene Glycol in Propylene Glycol-Contained Syrups by Ultrahigh-Performance Supercritical Fluid Chromatography-Mass Spectrometry after Precolumn Derivatization

Ethylene glycol (EG) and diethylene glycol (DEG) are two contaminants known to cause a variety of human health problems, when ingested in certain amounts, they can cause adverse effects such as nephrotoxicity, neurotoxicity and even death. They are widely found in propylene glycol, which is commonly used as a base for pharmaceutical syrups. The aim of this study was to develop an analytical method for the evaluation of EG and DEG in commercially available pediatric syrups. In this study, a fast, simple and reliable ultrahigh performance supercritical fluid chromatography-electrospray ionization-mass spectrometry (UHPSFC-ESI-MS) method was developed. The work involved the evaluation of three derivatization reagents for UHPSFC-ESI-MS. Benzoyl chloride was finally selected as the optimal derivatization reagent. Compared with an approach without derivatization, the present method achieved the separation and detection of EG and DEG efficiently, sensitively and rapidly, and analysis of EG and DEG in syrup formulations was realized within 7 min. The linear determination coefficients of EG and DEG in the concentration range of 0.25–25.0 μg/mL were greater than 0.999. The limits of detection for EG and DEG were 0.02 μg/mL and 0.07 μg/mL, respectively, and the limits of quantification were 0.09 μg/mL and 0.25 μg/mL, respectively. The recovery rates of DEG and EG ranged from 85.5%–108.1% and 86.7%–117.2%, respectively. The absolute values of the matrix effects in the three types of syrups considered were all less than 10%. Meanwhile, a gas chromatography-hydrogen flame ionization detection method was established for cross-testing of the analytical results. In 10 batches of syrup formulations, DEG was not detected by either method. The presence of EG was detected by UHPSFC-ESI-MS in only three batches, none of which exceeded 90.23 parts per million (ppm), with a mean absolute error of 5.95 ppm between the two sets of results. The developed UHPSFC-ESI-MS method was rapid, simple, efficient, sensitive and accurate for the determination of EG and DEG in genuine syrup formulations.

Liquid chromatography-tandem mass spectrometry analysis of nitrogen mustard degradation products after derivatization with benzoylimidazole

Nitrogen mustards are highly toxic compounds and strictly controlled by the Chemical Weapons Convention. When those agents are used, exposure must be confirmed by analyzing biological samples from victims to allow prompt medication and reduction of secondary damage. In this study, a derivatization-liquid chromatography (LC)-tandem mass spectrometry (MS/MS) method to analyze nitrogen mustard degradation products (ethanolamines; EAs) in human urine was developed. Benzoylimidazole (BzI) was used as a derivatization reagent, and two highly hydrophilic EAs (methyldiethanolamine and ethyldiethanolamine) were analyzed by using a reversed-phase column with sufficient retention. For urine samples, after solid-phase extraction with cation exchange cartridge and derivatization, EAs were analyzed at low limits of detection (5 ng/mL). The calibration curves had a wide linear range (50–1000 ng/mL), and the quantitation results were sufficient for screening. Compared with our previous derivatization-LC-MS/MS method using pentafluorobenzoyl chloride as a derivatization reagent and hydrophilic interaction liquid chromatography (HILIC)-MS/MS method, not only the limits of detection but also the operability and throughput were improved. The performance of the newly developed derivatization reagent was also evaluated using density functional theory (DFT) calculations.

Determination of double bond positions in unsaturated fatty acids by pre-column derivatization with dimethyl and dipyridyl disulfide followed by LC-SWATH-MS analysis.

Comprehensive in-depth structural characterization of free mono-unsaturated and polyunsaturated fatty acids often requires the determination of carbon-carbondouble bond positions due to their impact on physiological properties and relevance in biological samples or during impurity profiling of pharmaceuticals. In this research, we report on the evaluation of disulfides as suitable derivatization reagents for the determination of carbon-carbondouble bond positions of unsaturated free fatty acids by UHPLC-ESI-QTOF-MS/MS analysis and SWATH (sequential windowed acquisition of all theoretical mass spectra) acquisition. Iodine-catalyzed derivatization of C = C double bonds with dimethyl disulfide (DMDS) enabled detection of characteristic carboxy-terminal MS2 fragments for various fatty acids in ESI negative mode. The determination of double bond positions of fatty acids with up to three double bonds, the transfer of the method to plasma samples, and its limitations have been shown. To achieve charge-switching for positive ion mode MS-detection, derivatization with 2,2'-dipyridyldisulfide (DPDS) was investigated. It enabled detection of both corresponding characteristic omega-end- and carboxy-end-fragments for fatty acids with up to two double bonds in positive ion mode. It provides a straightforward strategy for designing MRM transitions for targeted LC-MS/MS assays. Both derivatization techniques represent a simple and inexpensive way for the determination of double bond positions in fatty acids with low number of double bonds. No adaptation of MS hardware is required and the specific isotopic pattern of resulting sulfur-containing products provides additional structural confirmation. This reaction scheme opens up the avenue of structural tuning of disulfide reagents beyond DMDS and DPDS using reagents like cystine and analogs to achieve enhanced performance and sensitivity.

B-147 Enhancing the Detection of Vitamin D Metabolites by LC-MS/MS Using a Novel Derivatization Kit

Abstract Background Vitamin D is crucial for various biological functions and exists in various tissues, including bones, intestines, and kidneys. 25-hydroxyvitamin D serves as a key marker for assessing vitamin D status in the body. Currently, LC-MS/MS is the gold standard for measuring vitamin D levels. The JeoQuant Kit for LC/MS Analysis of Vitamin D Metabolites (JEOL, Tokyo, Japan), which is used for the determination of vitamin D metabolites in serum based on the DAP-PA (Seki et al, 2019), enhances the ionization efficiency in the LC-MS/MS system for four vitamin D metabolites (25(OH)D3, 25(OH)D2, 24,25(OH)2D3 and 3-epi-25(OH)D3), enabling accurate fractionation and quantification. DAP-PA was developed as a caged Cookson-type reagent, demonstrating significantly enhanced stability compared to previous non-caged Cookson-type reagents. Our research aimed to assess whether the kit works practically. Methods The JeoQuant Kit contains internal standards of stable isotope-labelled compounds at appropriate concentrations, derivatization reagents, quality control materials derived from human serum and calibration materials. An Acquity H-Class UPLC coupled with an Acquity TQD mass spectrometer (Waters, MA, US) was used for analysis. CAPCELL CORE C18 2.1mm*100mm (Osaka-soda, Tokyo, Japan) was used as the analytical column. For the pretreatment, an Isolute SLE+ column (Biotage, Tokyo, Japan) was used. Eluent of LC-MS/MS was used 0.1% formic acid aqueous solution and 0.1% formic acid acetonitrile, with binary gradient. Results Using attached control L/H, reproducibility was shown by intra- and inter-assay CVs which were below 10% and 15%, respectively. Storage tests of derivatization agents at -20°C, 4°C, and room temperature for one week showed no significant difference on peak areas (one-way ANOVA). Through this derivatization, it was possible to achieve more than a 20-fold increase in sensitivity compared to measurements without derivatization. Notably, low concentrations of 3-epi-25(OH)D3 were distinctly separated and detected. Conclusions This study showed that the JeoQuant Kit effectively increases the sensitivity of vitamin D metabolites through derivatization. It also emphasized the reagent's notable stability. Furthermore, it enabled the detection of 3-epi-25(OH)D3 with less sensitive LC-MS/MS models, offering clear separation from 25(OH)D3. The kit, which is complete with calibrants, internal standards, and quality control samples, simplifies analytical procedures for vitamin D metabolite quantification, potentially aiding in developing Vitamin D- related biomarkers. Efforts to compare analytical performance of this kit with that of other methods are underway to establish its benefits.

Chemical Derivatization and Paper Spray Ionization Mass Spectrometry for Fast Screening of Retinoic Acid in Cosmetics.

As a prescription drug, retinoic acid is listed as a banned cosmetic additive in the EU and China regulations. Currently, spectrophotometric methods, including thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC), and HPLC-MS/MS, are commonly used for the determination of retinoic acid. As these conventional methods require complex pretreatment and are time-consuming, chemical derivatization combined with paper spray ionization mass spectrometry was developed for the fast detection of retinoic acid in cosmetics. N,N-dimethylpiperazine iodide (DMPI) was utilized as a derivatization reagent. Carboxylic acid in retinoic acid was derivatized to carry a positive charge and was subjected to mass spectrometry analysis. Results showed that compared with non-derivatized compounds, the detection limit was increased by about 50 times. The linearity in the range of 0.005-1 μg·mL-1 was good. The limit of detection (LOD) was 0.0013 μg·mL-1, and the limit of quantification (LOQ) was 0.0043 μg·mL-1. The recoveries of spiked samples were in the range of 95-105%, and the RSDs were below 5%. Derivatization and paper spray ionization MS render a quick, sensitive, and accurate method for the detection of retinoic acid in a complex matrix.

Determination of dimethyl sulfate genotoxic impurity in pantoprazole sodium sesquihydrate by derivatization method and UPLC/MS

In this study, a new method has been developed and, the method has been validated to analyze dimethyl sulfate (DMS) which known as a genotoxic impurity. DMS has been detected in trace levels within the drug substance pantoprazole sodium sesquihydrate using the derivatization method. Triethylamine has been used as derivatization reagent. Due to the highly polar nature of the derivatization product, which is a quaternary ammonium ion, a polar retention Hilic column has been used for chromatographic separation. The Waters QDA detector has been used in the single ion recording (SIR) mode at m/z 116 for the detection of the quaternary ammonium ion. In this study, the recovery rates have been achieved within the range of 96.46–105.98%. The LOD has been determined as 1.94E-07 mg/mL, and the LOQ has been determined as 6.46E-07 mg/mL. From the results, it can be said that the improved method in this study, would enables fast and reliable solutions for routine quality control analyses for DMS in API companies that especially is producing PSS.

Novel simultaneous analysis of 18 types of glycosaminoglycan-derived disaccharides using 4-aminobenzoic acid ethyl ester derivatization by HPLC with fluorescence detection.

Glycosaminoglycans (GAGs), including hyaluronic acid (HA), chondroitin sulfate (CS)/dermatan sulfate (DS), heparan sulfate (HS)/heparin (HP), and keratan sulfate (KS), play pivotal roles in living organisms. Generally, GAGs are analyzed after enzymatic digestion into unsaturated or saturated disaccharides. Due to high structural similarity between disaccharides, however, separation during analysis is challenging. Additionally, little is known about the structures of GAGs and their functional relationships. Elucidating the function of GAGs requires highly sensitive quantitative analytical methods. We developed a method for the simultaneous analysis of 18 types of disaccharides derived from HA (1 type), CS/DS (7 types), HS/HP (8 types), and KS (2 types) potentially detectable in analyses of human urine. The simple method involves HPLC separation with fluorescence detection following derivatization of GAG-derived disaccharides using 4-aminobenzoic acid ethyl ester (ABEE) as a pre-labeling agent and 2-picoline borane as a reductant. The ABEE derivatization reaction can be performed under aqueous conditions, and excess derivatization reagents can be easily, rapidly, and safely removed. This method enables highly sensitive simultaneous analysis of the 18 abovementioned types of GAG-derived disaccharides using HPLC with fluorescence detection in small amounts of urine (1mL) in a single run. The versatile method described here could be applied to the analysis of GAGs in other biological samples.