•Development of an on-line post column photochemical derivatization of AFM1.•Environmental friendly approach which eliminates halogenated and hazardous solvent.•The substitution of acetonitrile by ...methanol as mobile phase resulted in ∼67% enhancement of peak area of AFM1.
The determination of aflatoxin M1 in milk using high performance liquid chromatography with photochemical post-column derivatization and fluorescence detection is described. The samples were first extracted and clean–up using the immunoaffinity AFLATEST column originally targeted for aflatoxins B1, B2, G1 and G2. The separation of aflatoxin M1 were performed using C18 Hypersil gold (150mm×4.6mm, 5μm) column at 40°C under isocratic elution. Fluorescence detector (FLD) was set at 360nm and 440nm as excitation and emission, respectively. The use of methanol to replace acetonitrile as the mobile phase resulted in ∼67% peak area enhancement of AFM1. The limit of detection (LOD) and quantification (LOQ) of the analytical method after post-column derivatization without evaporation/reconstitution with mobile phase was 0.0085μgL−1 and 0.025μgL−1 respectively. However, LOD and LOQ improved to 0.002 and 0.004μgL−1 respectively with the addition of evaporation/reconstitution step. The method was statistically validated, showing linear response (R2>0.999), good recoveries (85.2–107.0%) and relative standard deviations (RSD) were found to be ≤7%. The proposed method was applied to determine AFM1 contamination in various types of milk and milk products. Only 2 samples were contaminated with aflatoxin M1 (10% incidence). However, the contamination level is below the Malaysian and European legislation limits.
•LC/ESI–MS/MS has been widely used for the quantification of endogenous steroids.•However, the ESI efficiency and fragmentation behavior of some steroids are poor.•Chemical derivatization is ...effective for enhancing detectability of steroids.•This article reviews chemical derivatization for LC/ESI–MS/MS of steroids.•Stable isotope-coded derivatization for the steroid analysis is also described.
Sensitive and specific methods for the detection, characterization and quantification of endogenous steroids in body fluids or tissues are necessary for the diagnosis, pathological analysis and treatment of many diseases. Recently, liquid chromatography/electrospray ionization–tandem mass spectrometry (LC/ESI–MS/MS) has been widely used for these purposes due to its specificity and versatility. However, the ESI efficiency and fragmentation behavior of some steroids are poor, which lead to a low sensitivity. Chemical derivatization is one of the most effective methods to improve the detection characteristics of steroids in ESI–MS/MS. Based on this background, this article reviews the recent advances in chemical derivatization for the trace quantification of steroids in biological samples by LC/ESI–MS/MS. The derivatization in ESI–MS/MS is based on tagging a proton-affinitive or permanently charged moiety on the target steroid. Introduction/formation of a fragmentable moiety suitable for the selected reaction monitoring by the derivatization also enhances the sensitivity. The stable isotope-coded derivatization procedures for the steroid analysis are also described.
Research Advances on Matrine Sun, Xiao-Ying; Jia, Li-Yi; Rong, Zheng ...
Frontiers in chemistry,
04/2022, Letnik:
10
Journal Article
Recenzirano
Odprti dostop
Matrine is an alkaloid extracted from traditional Chinese herbs including
,
,
root, etc. It has the dual advantages of traditional Chinese herbs and chemotherapy drugs. It exhibits distinct benefits ...in preventing and improving chronic diseases such as cardiovascular disease and tumors. The review introduced recent research progresses on extraction, synthesis and derivatization of Matrine. The summary focused on the latest research advances of Matrine on anti-atherosclerosis, anti-hypertension, anti-ischemia reperfusion injury, anti-arrhythmia, anti-diabetic cardiovascular complications, anti-tumor, anti-inflammatory, anti-bacterium, anti-virus, which would provide new core structures and new insights for new drug development in related fields.
The present study describes a sensitive, efficient, and easy approach for isolation, enrichment, and derivatization some phenolic compounds in the beverage samples packed in plastic bottles. The ...sample preparation method is based on a hollow fiber–liquid phase microextraction technique using a deep eutectic solvent. The enriched analytes are determined by gas chromatography–mass spectrometry. For this purpose, a new deep eutectic solvent composed of 8–hydroxyquinoline and pivalic acid is synthesized and used as an extraction solvent. The solvent is mixed with chloroacetyl chloride as a derivatization agent and filled into a hollow fiber segment containing an iron wire within the lumen. The prepared stir bar (hollow fiber) is stirred into the sample solution in which sodium chloride is dissolved to increase ionic strength of the solution. Temperature of the solution is adjusted at 50 °C to improve efficiency of the extraction/derivatization procedure. Under optimum conditions, the introduced method indicated high enhancement (1652–3265) and enrichment (1085–1256) factors, low limits of detection (9–22 ng L−1) and quantification (29–76 ng L−1), good linearity (r2 ≥ 0.9950), and satisfactory repeatabilities. Finally, the proposed method was applied in analysis of the analytes in the various beverage samples packed in plastic packages.
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•A DES-HF-LPME method was developed for extraction/derivatization of PCs.•New DESs composed of 8–hydroxyquinoline and carboxylic acids were prepared.•The analytes were derivatized using chloroacetyl chloride.•PCs contents of some beverage samples packed in plastic bottles were determined.
•Proposed naphthylamine microwave-assisted derivatization was fast and efficient.•Polypropylene membrane MMSPE devices are promising for aromatic amine extraction.•Obtained devices are viable low ...cost alternatives for aromatic amine biomonitoring.•This is the first use polypropylene membrane MMSPE devices with biological fluids.
Exposure to tobacco smoke is highly correlated to the incidence of different types of cancer due to various carcinogenic compounds present in such smoke. Aromatic amines, such as 1-naphthylamine (1-NA) and 2-naphthylamine (2-NA), are produced in tobacco burning and are linked to bladder cancer. Miniaturized solid phase extraction techniques, such as microporous membrane solid phase extraction (MMSPE), have shown potential for the extraction of aromatic compounds. In this study, a bioanalytical method for the determination of 1-NA and 2-NA in human urine was developed using polypropylene microporous membranes as a sorptive phase for MMSPE. Urine samples were hydrolyzed with HCl for 1 h at 80 °C, after which pH was adjusted to 10. Ultrasound-assisted MMSPE procedure was optimized by factorial design as follows. To each sample, 750 µL of methanol was added, and ultrasound-assisted MMSPE was conducted for 1 h with four devices containing seven 2 mm polypropylene membrane segments. After extraction, the segments were transferred to 400 µL of hexane, and desorption was conducted for 30 min. Extracts were submitted to a simple and fast microwave-assisted derivatization procedure, by the addition of 10 µL of PFPA and heating at 480 W for 3 min, followed by clean-up with phosphate buffer pH 8.0 and GC–MS/MS analysis. Adequate linearity was obtained for both analytes in a range from 25 to 500 µg L−1, while the multiple reaction monitoring approach provided satisfactory selectivity and specificity. Intra-day (n = 6) and inter-day (n = 5) precision and accuracy were satisfactory, below 15 % and between 85 and 115 %, respectively. Recovery rates found were 91.9 and 58.4 % for 1-NA and 2-NA, respectively, with adequate precision. 1-NA was found in first-hand smokers’ urine samples in a concentration range from 20.98 to 89.09 µg in 24 h, while it could be detected in second-hand smoker's urine samples, and 2-NA detected in all first and second-hand smokers’ urine samples. The proposed method expands the applicability of low cost MMSPE devices to aromatic amines and biological fluids.
•A high throughput method was developed to identify carbonyl molecules in DOM.•Carbonyl molecules occupied high relative abundance in NOM samples.•N- and Cl-containing carbonyl molecules were ...produced after chlorination.•DOM-ferrihydrite interaction induced the formation of carbonyl molecules.
Carbonyl compounds are important components of natural organic matter (NOM) with high reactivity, so that play a pivotal role in the dynamic transformation of NOM. However, due to the lack of effective analytical methods, our understanding on the molecular composition of these carbonyl compounds is still limited. Here, we developed a high-throughput screening method to detect carbonyl molecules in complex NOM samples by combining chemical derivatization with electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR-MS). In six different types of dissolved organic matter (DOM) samples tested in this study, 20–30 % of detected molecules contained at least one carbonyl group, with relative abundance accounted for 45–70 %. These carbonyl molecules displayed lower unsaturation level, lower molecular weight, and higher oxidation degree compared to non-carbonyl molecules. More importantly, the measured abundances of carbonyl molecules were consistent with the results of 13C nuclear magnetic resonance (NMR) analysis. Based on this method, we found that carbonyl molecules can be produced at DOM-ferrihydrite interface, thus playing a role in shaping the molecular diversity of DOM. This method has broad application prospects in screening carbonyl compounds from complex mixtures, and the same strategy can be used to directional identification of molecules with other functional groups as well.
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Short-chain fatty acids (SCFAs) are major gut microbiota-derived metabolites, which can reshape the intestine and regulate gut immunity. The application of conventional GC methods has been hampered ...for quantifying low-concentrated SCFAs, such as in serum, saliva, and digesta of germ-free animals. Herein, we established a LC–MS method to quantify SCFAs after 5-(dimethylamino)-1-carbohydrazide-isoquinoline (DMAQ) derivatization. The DMAQ derivatization significantly enhanced the detection sensitivity and improved separation of SCFAs. 2-methylbutyric acid and 3-methylbutyric acid were separately quantitated. Moreover, the matrix effect was diminished using DMAQ-13C/15N-tagged SCFAs as internal standards. The established quantitation method was successfully applied in the analysis of plasma and cecum digesta collected from neonatal piglets, revealing that significant increases in biological SCFA contents in cecum digesta were closely related to the variation of gut microbial diversity. The established quantitation method is capable of sensitively and comprehensively quantifying SCFAs that may provide insights into underlying gut-microbiota functions.
One of the most valuable practices for analyzing not-so-analytical-friendly analytes in complex, heterogenous matrices is derivatization. Availability of numerous derivatizing reagents (DRs) makes ...the modification of analyte more exploitable in terms of an analytical perspective. A wide array of derivatization techniques like pre or post-column, in-situ, enzymatic, ultrasound-assisted, microwave-assisted, photochemical derivatization has added much-needed methodological strength in analyzing intricate analytical matrices (food, water, and soil). In recent years, analytical chemistry has achieved greater heights through the development of new sensitive methods with simple conventional instruments like High-Performance Liquid Chromatography (HPLC) devoid of Mass detectors. The prompt availability of these straightforward instruments also makes it a favorable option for routine analysis in food, environmental, bioanalytical chemistry. Analyzing food, environmental or bioanalytical specimen has some of the most problematic aspects, like the low concentration of the analytes accompanied by not too suitable analytical properties. Even though conventional HPLC lacks the required sensitivity but merger with derivatization can lead to a remarkable increase in sensitivity. In recent years there has been a lot of application of diverse derivatizations to increase the sensitivity and selectivity of the analyte for available instruments, resulting in notable findings. Therefore, this review describes the application of derivatization principles in the analysis of analytes in food and additional matrices using conventional HPLC instruments such as HPLC-UV, HPLC-DAD, and HPLC-FD. In this article, we will briefly review the different modes and multiple types of derivatizing reagents with their mechanisms and importance for encouraging the use of established HPLC instruments.
L-p-Boronophehylalanine (BPA) is used in boron neutron capture therapy (BNCT), which is a novel selective cancer radiotherapy technique. It is important to measure BPA levels in human blood for ...effective radiotherapy; a prompt gamma-ray spectrometer, ICP-AES, and ICP-MS have been used for this purpose. However, these methods require sophisticated and expensive apparatuses as well as experienced analysts. Herein, we propose an HPLC-FL method for the determination of BPA after precolumn derivatization. A new fluorogenic reagent for aryl boronic acid derivatives, namely, 4-iodobenzonitrile, was employed for the fluorogenic derivatization of BPA based on the Suzuki coupling reaction.
After the fluorogenic derivatization, a fluorescent cyanobiphenyl derivative is formed with maximum fluorescence at 335 nm after excitation at 290 nm. The developed method showed good linearity (r2=0.997) over the concentration range of 0.5–1000 nmol/L, and the detection limit (S/N = 3) was 0.26 nmol/L. The proposed method is more sensitive than previously reported methods for the determination of BPA, including the ICP-MS. Finally, the proposed method was successively applied to the measurement of BPA in human whole blood samples with a good recovery rate (≥95.7 %) using only 10 μL of blood sample. The proposed method offers a simple and efficient solution for monitoring BPA levels in BNCT-treated patients.
4-Iodobenzonitrile was investigated as a new fluorogenic reagent for BPA based on Suzuki coupling. A new HPLC-FL method for BPA in whole blood samples with ultrasensitivity was developed. The developed method is superior in sensitivity to all previously reported methods for BPA. The method requires only a very small sample volume, making it suitable for micro-blood analysis of BPA via fingerstick sampling.
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•4-Iodobenzonitrile as a new fluorogenic reagent for L-p-boronophenylalanine (BPA).•Characterization of the formed fluorescent cyano biphenyl derivative with tandem mass spectrometry.•HPLC-fluorescence method for BPA was ultra-sensitivity down to 0.26 nM.•Analysis of BPA in a very small volume of whole blood samples down to 10 μL.•The BPA was analyzed with excellent recovery not less than 95.7 % from whole blood.
For over a century, the importance of lipid metabolism in biology was recognized but difficult to mechanistically understand due to the lack of sensitive and robust technologies for identification ...and quantification of lipid molecular species. The enabling technological breakthroughs emerged in the 1980s with the development of soft ionization methods (Electrospray Ionization and Matrix Assisted Laser Desorption/Ionization) that could identify and quantify intact individual lipid molecular species. These soft ionization technologies laid the foundations for what was to be later named the field of lipidomics. Further innovative advances in multistage fragmentation, dramatic improvements in resolution and mass accuracy, and multiplexed sample analysis fueled the early growth of lipidomics through the early 1990s. The field exponentially grew through the use of a variety of strategic approaches, which included direct infusion, chromatographic separation, and charge-switch derivatization, which facilitated access to the low abundance species of the lipidome. In this Thematic Review, we provide a broad perspective of the foundations, enabling advances, and predicted future directions of growth of the lipidomics field.
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