Amount Of Derivatization Reagent Research Articles

Nanoconfined liquid phase nanoextraction combined with in-fiber derivatization for simultaneous quantification of seventy amino-containing metabolites in plasma by LC-MS/MS: Exploration of lung cancer screening model

Targeted metabolomics with absolute quantification is widely applied in biomarker identification and drug screening. However, due to the complexity of biological matrix and trace amount of metabolites in plasma, simultaneous quantification of highly polar metabolites in plasma with broad coverage in short time is still challenging. Herein, we proposed a nanoconfined liquid phase nanoextraction (NLPNE) combined with in-fiber derivatization (IFD) strategy that enabled simultaneous quantification of seventy amino-containing analytes in plasma, including amines, nucleosides and their metabolites. Methanol−water (2:1, v/v) was selected as nanoconfined solvent (NCS) to quickly extract highly polar analytes based on the nanoconfinement effect, followed by IFD process directly performed by adding the derivatization reagent benzoyl chloride (BzCl) within 5 min. Besides saving time, this combination strategy was environment-friendly with little organic solvent consumption and cost-effective by using reusable carbon nanofibers. Furthermore, the sensitivity was increased up to 4.92-fold compared with protein precipitation (PP) based conventional derivatization method. Key factors that affected derivatization efficiency including the derivatization time, the amount of derivatization reagent, desorption solution and CNFs, were optimized by response surface methodology (RSM). After systematical method validation, this methodology was applied to determine the multi-metabolites index in plasma of lung cancer using an integrated data processing workflow. Then lung cancer diagnosis model was established through binary logistic regression analysis to make a reference for quick lung cancer screening clinically. Taken together, the NLPNE-IFD LC-MS/MS method for targeted metabolomics enables simultaneous quantification of seventy amino-containing analytes with advantages of broad coverage, high sensitivity, time- and solvent-saving, which could be used on cancer diagnosis clinically.

Simultaneous determination of seven endogenous aldehydes in human blood by headspace gas chromatography–mass spectrometry

Endogenous aldehydes (EAs) formed by the free-radical-mediated reaction are regarded as potential biological markers of several diseases. In this work, an automated and solvent-free analytical method was developed for quantitative analysis of seven EAs (C1–C7) in human blood by using gas chromatography–mass spectrometry coupled with a headspace generator sampler (HS-GC–MS). A 1:4 (blood:water) dilution and the 1,2‑dibromopropane internal standard were introduced to reduce the influence of the matrix effect from complex biological fluids. The sample preparation steps were simplified. Various experimental parameters for derivatization and extraction conditions were studied such as HS extraction temperature and time, the amount of derivatization reagent, pH and the salt effect. Under these optimum conditions, seven low-mass aldehydes were separated and analyzed within 10 min. Additionally, this method achieved limits of detection in the range of 0.0692–0.864 μg/L, an excellent linearity with correlation coefficients higher than 0.9996 and appropriate repeatability and reproducibility values (RSD < 12% at low, middle and high levels). The HS-GC–MS method was applied to measure the concentrations of the seven aldehydes in blood from bladder cancer patients (n = 15) and control subjects (n = 15). Compared with the control subjects, the levels of butanal (p < 0.01), formaldehyde, acetaldehyde, propanal, pentanal, hexanal and heptanal (all p < 0.001) were increased significantly, indicating that EAs may be useful as biomarkers in the early diagnosis of bladder cancer.

Ultrasound‐Assisted Emulsification‐Microextraction With In Situ Derivatization and Gas Chromatography‐Electron‐Capture Detection for Determination of Chlorophenols in Water

A new method, ultrasound‐assisted emulsification–microextraction (USAEME) with in situ derivatization and gas chromatography‐electron‐capture (GC‐μ‐ECD) detection, was developed to determine selected chlorophenols (CPs), including 2‐chlorophenol, 2,6‐dichlorophenol, 2,4,5‐trichlorophenol, 2,3,4,6‐tetrachlorophenol, and pentachlorophenol in water and wastewater samples. Initially the suitable solvent was determined and amount of derivatization reagent (acetic anhydride) and K2CO3, other experimental variables involving extraction and derivatization time, volume of extraction solvent and sample ionic strength, were optimized employing a 23 factorial experimental design. The developed method employed 100 μL of chloroform as extraction solvent, extraction with in situ derivatization for 10 min using 100 µL of acetic anhydride and 100 µL K2CO3 (5%, w/v) for 5 mL samples at 25°C with no ionic strength adjustment and centrifugation for 5 min at 4000 rpm. The average relative recoveries under optimum conditions were &gt;97% with relative standard deviation (RSD) ≤5% for three different spiking levels (5, 20, and 100 μg L‐1). The limits of detection for studied CPs were in the range of 0.007–0.011 μg L−1. The developed USAEME with in situ derivatization method was successfully applied to real water samples such as tap, dam water, and domestic wastewater. The developed method showed comparable efficiency with conventional liquid–liquid extraction‐derivatization coupled with GC‐μ‐ECD. The results demonstrated that the developed USAEME with in situ derivatization is simple, fast and reliable for determination of selected CPs in water samples by GC‐μ‐ECD.

Determination of Fatty Acids in Three Nitraria Species by Precolumn Fluorescence Labeling for High-Performance Liquid Chromatography and Atmospheric Pressure Chemical Ionization–Mass Spectrometry

A novel fluorescence method using 2-(7-methyl-1H-pyrazolo-[3,4-b] quinoline-1-yl) ethyl-4-methyl benzenesulfonate as the labeling reagent was established for high-performance liquid chromatography determination of fatty acids. The conditions were optimized, including the identity of the organic solvent, identity, and amount of catalyst, amount of derivatization reagent, derivatization temperature, and derivatization time. The results indicated that quantitative yields of derivative were obtained with a five-fold molar excess of reagent at 90°C for 30 min using 25 mg of potassium carbonate as the catalyst. Atmospheric pressure chemical ionization mass spectrometry results indicated that collision-induced dissociation of protonated fatty acid derivatives produced fragments at m/z 228.2, m/z 210.2, and m/z 183.8. The method was validated in terms of linearity, limits of detection, limits of quantification, precision, and accuracy, and the results showed that the method exhibited excellent sensitivity, selectivity, and reproducibility. Limits of detection and limits of quantification were in the ranges of 0.52–2.34 ng mL−1 and 1.23–6.63 ng mL−1, respectively. This method was successfully applied to the determination of fatty acids in sarcocarps, seeds, and leaves of Nitraria tangutorum Bobr., Nitraria sibirica Pall., and Nitraria roborowskii Kom. The results indicated that the main components were oleic, linoleic, linolenic, and hexadecanoic acids. However, the composition of fatty acids in the tissues varied considerably.

Sensitive determination of the potential biomarker sarcosine for prostate cancer by LC-MS withN,N′-dicyclohexylcarbodiimide derivatization

Sarcosine, a potential biomarker of prostate cancer, has drawn great attention in recent years. However, controversial research keeps arising about its role as a biomarker that might come from the two isomers (α-alanine and β-alanine) of sarcosine due to their same molecular weight and similar properties, which could interfere with the accurate detection of sarcosine. In this study, a simple and sensitive method was developed for the detection of sarcosine and the two isomers by LC with ion-trap MS through a novel derivatization reagent N,N'-dicyclohexylcarbodiimide. N,N'-Dicyclohexylcarbodiimide is usually considered as a condensation reagent, however, it was directly used as a derivatization reagent through a rearrangement side reaction in this study. The proposed method not only improved the chromatographic retention behavior of sarcosine and its two isomers, which was a benefit to their separation, but also dramatically enhanced the detection sensitivity of sarcosine, which was more favorable for real sample analysis. The factors affecting the productivity of the derivatization reaction, such as reaction time and amount of derivatization reagent, were systematically optimized. The method shows good linearity (R(2) > 0.99), sensitivity with LODs of sarcosine as low as 1 ng/mL, and repeatability with the RSD < 6.07%. The developed method was applied to the analysis of urine.

A new fluorescent derivatization reagent and its application to free fatty acid analysis in pomegranate samples using HPLC with fluorescence detection

A new fluorescent labeling reagent has been developed for the determination of fatty acids (FAs) by HPLC with fluorescence detection. The derivatization conditions including the amount of derivatization reagent, temperature, and type of catalyst were investigated, the results indicated that the reaction proceeded within 30 min at 90°C in the presence of K2CO3 catalyst. The maximal yield was obtained with a four- to fivefold molar reagent excess. The derivatives exhibited strong fluorescence with an excitation maximum at λex = 245 nm and an emission maximum at λem = 410 nm. Twenty-five FA derivatives were well separated by RP-HPLC on a Hypersil BDS C8 column in combination with gradient elution. All FAs were found to give excellent linear responses with correlation coefficients >0.9992. The method gave a low LOQ of 0.85–5.5 ng/mL (S/N of 10). The developed method was employed to analyze free FAs (FFAs) composition in pomegranate samples without any purification. FFAs in samples were doubly identified by HPLC retention time and protonated molecular ion corresponding to m/z [M+H]+. This newly developed method allows a highly sensitive determination of trace FFAs from pomegranate and other foodstuffs.

Simultaneous determination of main reaction components in the reaction mixture during biodiesel production

The proposed analytical method allows for simultaneous determination by GC using a programed temperature vaporization injector and a flame ionization detector of the main reaction components (i.e. glycerol, methyl esters, mono-, di-, and triacylglycerols) in the reaction mixture during biodiesel production. The suggested method is convenient for the rapid and simple evaluation of the kinetic data gained during the transesterification reaction and, also partially serves as an indicator of the quality of biodiesel and mainly, as the indicator of the efficiency of the whole production process (i.e. the conversion of triacylglycerols to biodiesel and its time progress). The optimization of chromatographic conditions (e.g. the oven temperature program, injector setting, amount of derivatization reagent, and the derivatization reaction time) was performed. The method has been validated with crude samples of biodiesel made from waste-cooking oils in terms of linearity, precision, accuracy, sensitivity, and limits of detection and quantification. The results confirmed a satisfactory degree of accuracy and repeatability (the mean RSDs were usually below 2%) necessary for the reliable quantitative determination of all components in the considerable concentration range (e.g. 10-1100 μg/mL in case of methyl esters). Compound recoveries ranging from 96 to 104% were obtained.

Surfactant-Based Ultrasound-Assisted Dispersive Liquid-Liquid Microextraction Determination of Corticosteroids Followed by HPLC-DAD

Surfactant-based ultrasound-assisted dispersive liquid–liquid microextraction (UA-DLLME) and derivatization were applied for the pretreatment of three corticosteroids prior to determination by high-performance liquid chromatography diode array detector (HPLC-DAD). An appropriate mixture of Triton X-100 (disperser solution), CCl4(Carbon tetrachloride; extraction solvent), and salicylaldehyde (derivatization reagent) was added to human urine and plasma samples. Extraction and derivatization were continuously performed. Some key parameters, including the nature and volume of extraction solvent and dispersive solvent, amount of derivatization reagent, extraction time and temperature effect were investigated. Linearity was investigated from 1 to 300 ng mL−1. All correlation coefficients of the calibration curves were higher than 0.9993. The recoveries of 80.36% to 87.60% and an enrichment factor of 50 were obtained with only 5.00 mL of sample. The LODs thus estimated were 0.014 ng mL−1 for beclomethasone dipropionate, 0.021 ng mL−1 for hydrocortisone, and 0.314 ng mL−1 for Nandroloniphenylpropionas, respectively, while the relative standard deviations(RSD) varied between 1.66% and 2.72% (n = 6). The results showed that the method is applicable to the determination of trace corticosteroids in human urine and plasma samples.

An in situ benzoylation-dispersive liquid–liquid microextraction method based on solidification of floating organic droplets for determination of biogenic amines by liquid chromatography–ultraviolet analysis

A novel analytical method consisting of in situ derivatization combined with liquid phase microextraction followed by liquid chromatography–ultraviolet detection (LC–UV) was developed to determine the biogenic amines (BAs) of alcoholic beverages. Nine BAs (putrescine, cadaverine, 1,3-diaminopropane, tryptamine, phenylethylamine, spermidine, spermine, histamine, and tyramine) were derivatized in situ with benzoyl chloride, extracted by dispersive liquid–liquid microextraction based on solidification of floating organic droplets (DLLME-SFO), and then chromatographed by LC–UV. Factors influencing the derivatization and extraction efficiency were optimized, including the reaction buffer pH and concentration, amount of derivatization reagent, reaction time, types and volumes of extraction and dispersive solvents, and extraction time. Under the optimized conditions, the method was linear over 0.05–8.0μgmL−1 with an r2≥0.992 and exhibited intra- and inter-day precision less than 8.8% and 11.5%, respectively. The limit of detection ranged between 0.005 and 0.01μgmL−1. The developed method using a basic LC–UV system is sensitive, rapid, convenient, green, and cost-effective. Moreover, it is versatile and practical for the analysis of BAs, as demonstrated by the successful application in four different types of popular alcoholic beverages (white wine, red wine, rice wine, and beer).

Determination of four phenolic endocrine disrupting chemicals in Dianchi Lake, China

An efficient derivatization method using phenyltrimethylammonium (PTA-OH) has been developed to determine simultaneously four phenolic endocrine disrupting chemicals, 4-n-nonylphenol (4-n-NP), 4-tert-octylphenol (4-t-OP), bisphenol A (BPA) and 4-cumylphenol (4-CP) in surface water of Dianchi Lake (China) by solid-phase extraction (SPE) and gas chromatography-mass spectrometry (GC-MS). Compared with silylation of target phenols using N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) + 1% trimethylchlorosilane (TMCS), methylation by PTA-OH displayed a higher response and stability based on the investigations of various derivatization conditions, including derivatization solvent, amount of derivatization reagent, reaction temperature and time. Experiments were carried out to examine the performance of the proposed method based on the correlation coefficient, the method quantification limit (MQL), mean recovery rate and relative standard deviation (RSD). Under optimum derivatization conditions, MQLs of the methylated target compounds were all below 1 ng L−1. Results revealed that the proposed method exhibited a satisfactory precision and reproducibility for the separation and determination of target phenols. The proposed method had been applied to determine four phenols in surface water of Dianchi Lake located in southwest of China. The concentrations of 4-n-NP, 4-t-OP, BPA and 4-CP were determined to be 13.6-141.6 ng L−1, N.D.-56.5 ng L−1, N.D.- 4713.6 ng L−1 and 23.3-48.5 ng L−1, respectively.

Microwave-assisted one-step extraction-derivatization for rapid analysis of fatty acids profile in herbal medicine by gas chromatography-mass spectrometry

A rapid and practical microwave-assisted one-step extraction-derivatization (MAED) method was developed for gas chromatography-mass spectrometry analysis of fatty acids profile in herbal medicine. Several critical experimental parameters for MAED, including reaction temperature, microwave power and the amount of derivatization reagent (methanol), were optimized with response surface methodology. The results showed that the chromatographic peak areas of total fatty acids and total unsaturated fatty acids content obtained with MAED were markedly higher than those obtained by the conventional Soxhlet or microwave extraction and then derivatization method. The investigation of kinetics and thermodynamics of the derivatization reaction revealed that microwave assistance could reduce activation energy and increase the Arrhenius pre-exponential factor. The MAED method simplified the sample preparation procedure, shortened the reaction time, but improved the extraction and derivatization efficiency of lipids and reduced ingredient losses, especially for the oxidization and isomerization of unsaturated fatty acids. The simplicity, speed and practicality of this method indicates great potential for high throughput analysis of fatty acids in natural medicinal samples.

Ionic liquid-based microwave-assisted dispersive liquid–liquid microextraction and derivatization of sulfonamides in river water, honey, milk, and animal plasma

The ionic liquid-based microwave-assisted dispersive liquid–liquid microextraction (IL-based MADLLME) and derivatization was applied for the pretreatment of six sulfonamides (SAs) prior to the determination by high-performance liquid chromatography (HPLC). By adding methanol (disperser), fluorescamine solution (derivatization reagent) and ionic liquid (extraction solvent) into sample, extraction, derivatization, and preconcentration were continuously performed. Several experimental parameters, such as the type and volume of extraction solvent, the type and volume of disperser, amount of derivatization reagent, microwave power, microwave irradiation time, pH of sample solution, and ionic strength were investigated and optimized. When the microwave power was 240 W, the analytes could be derivatized and extracted simultaneously within 90 s. The proposed method was applied to the analysis of river water, honey, milk, and pig plasma samples, and the recoveries of analytes obtained were in the range of 95.0–110.8, 95.4–106.3, 95.0–108.3, and 95.7–107.7, respectively. The relative standard deviations varied between 1.5% and 7.3% ( n = 5). The results showed that the proposed method was a rapid, convenient and feasible method for the determination of SAs in liquid samples.

An Optimized Method for the Measurement of Acetaldehyde by High‐Performance Liquid Chromatography

Acetaldehyde is produced during ethanol metabolism predominantly in the liver by alcohol dehydrogenase and rapidly eliminated by oxidation to acetate via aldehyde dehydrogenase. Assessment of circulating acetaldehyde levels in biological matrices is performed by headspace gas chromatography and reverse phase high-performance liquid chromatography (RP-HPLC). We have developed an optimized method for the measurement of acetaldehyde by RP-HPLC in hepatoma cell culture medium, blood, and plasma. After sample deproteinization, acetaldehyde was derivatized with 2,4-dinitrophenylhydrazine (DNPH). The reaction was optimized for pH, amount of derivatization reagent, time, and temperature. Extraction methods of the acetaldehyde-hydrazone (AcH-DNP) stable derivative and product stability studies were carried out. Acetaldehyde was identified by its retention time in comparison with AcH-DNP standard, using a new chromatography gradient program, and quantitated based on external reference standards and standard addition calibration curves in the presence and absence of ethanol. Derivatization of acetaldehyde was performed at pH 4.0 with an 80-fold molar excess of DNPH. The reaction was completed in 40 minutes at ambient temperature, and the product was stable for 2 days. A clear separation of AcH-DNP from DNPH was obtained with a new 11-minute chromatography program. Acetaldehyde detection was linear up to 80 μM. The recovery of acetaldehyde was >88% in culture media and >78% in plasma. We quantitatively determined the ethanol-derived acetaldehyde in hepatoma cells, rat blood and plasma with a detection limit around 3 μM. The accuracy of the method was <9% for intraday and <15% for interday measurements, in small volume (70 μl) plasma sampling. An optimized method for the quantitative determination of acetaldehyde in biological systems was developed using derivatization with DNPH, followed by a short RP-HPLC separation of AcH-DNP. The method has an extended linear range, is reproducible and applicable to small-volume sampling of culture media and biological fluids.

Multistep derivatization method for the determination of multifunctional oxidation products from the reaction of α-pinene with ozone

A novel three-step analytical method was developed which enables the simultaneous detection and identification of multifunctional oxygenated products resulting from the reaction of α-pinene with ozone. The method consists of the following steps: conversion of carbonyl groups to methyloximes using methyloxyamine, conversion of carboxylic acids to methyl esters using trimethylsilyldiazomethane (TMSD), and conversion of alcohols to trimethylsilyl ethers using N,O-bis(trimethylsilyl)-trifluoroacetamide (BSTFA). The derivatization procedure at each stage was optimized yielding the appropriate amount of derivatization reagent, reaction temperature and time. The newly developed analytical procedure manages without processes of extraction and evaporation to dryness at any stage. Total time for sample analysis is short ca. 3 h. The characteristic ions of derivatives and common pattern for ion fragmentation in capillary gas chromatography electron impact mass spectrometry (GC–EI–MS) analysis were elucidated and discussed.

Determination of octylphenol and nonylphenol in aqueous sample using simultaneous derivatization and dispersive liquid–liquid microextraction followed by gas chromatography–mass spectrometry

A simple and fast sample preparation method for the determination of nonylphenol (NP) and octylphenol (OP) in aqueous samples by simultaneous derivatization and dispersive liquid–liquid microextraction (DLLME) was investigated using gas chromatography–mass spectrometry (GC/MS). In this method, a combined dispersant/derivatization catalyst (methanol/pyridine mixture) was firstly added to an aqueous sample, following which a derivatization reagent/extraction solvent (methyl chloroformate/chloroform) was rapidly injected to combine in situ derivatization and extraction in a single step. After centrifuging, the sedimented phase containing the analytes was injected into the GC port by autosampler for analysis. Several parameters, such as extraction solvent, dispersant solvent, amount of derivatization reagent, derivatization and extraction time, pH, and ionic strength were optimized to obtain higher sensitivity for the detection of NP and OP. Under the optimized conditions, good linearity was observed in the range of 0.1–1000 μg L −1 and 0.01–100 μg L −1 with the limits of detection (LOD) of 0.03 μg L −1 and 0.002 μg L −1 for NP and OP, respectively. Water samples collected from the Pearl River were analyzed with the proposed method, the concentrations of NP and OP were found to be 2.40 ± 0.16 μg L −1 and 0.037 ± 0.001 μg L −1, respectively. The relative recoveries of the water samples spiked with different concentrations of NP and OP were in the range of 88.3–106.7%. Compared with SPME and SPE, the proposed method can be successfully applied to the rapid and convenient determination of NP and OP in aqueous samples.

Analysis of volatile aldehyde biomarkers in human blood by derivatization and dispersive liquid–liquid microextraction based on solidification of floating organic droplet method by high performance liquid chromatography

A new dispersive liquid–liquid microextraction based on solidification of floating organic droplet method (DLLME-SFO) was developed for the determination of volatile aldehyde biomarkers (hexanal and heptanal) in human blood samples. In the derivatization and extraction procedure, 2,4-dinitrophenylhydrazine (DNPH) as derivatization reagent and formic acid as catalyzer were injected into the sample solution for derivatization with aldehydes, then the formed hydrazones was rapidly extracted by dispersive liquid–liquid microextraction with 1-dodecanol as extraction solvent. After centrifugation, the floated droplet was solidified in an ice bath and was easily removed for analysis. The effects of various experimental parameters on derivatization and extraction conditions were studied, such as the kind and volume of extraction solvent and dispersive solvent, the amount of derivatization reagent, derivatization temperature and time, extraction time and salt effect. The limit of detections (LODs) for hexanal and heptanal were 7.90 and 2.34 nmol L −1, respectively. Good reproducibility and recovery of the method were also obtained. The proposed method is an alternative approach to the quantification of volatile aldehyde biomarkers in complex biological samples, being more rapid and simpler and providing higher sensitivity compared with the traditional dispersive liquid–liquid microextraction (DLLME) methods.

Determination of chlorophenols in water samples using simultaneous dispersive liquid–liquid microextraction and derivatization followed by gas chromatography-electron-capture detection

Simultaneous dispersive liquid–liquid microextraction (DLLME) and derivatization combined with gas chromatography-electron-capture detection (GC-ECD) was used to determine chlorophenols (CPs) in water sample. In this derivatization/extraction method, 500 μL acetone (disperser solvent) containing 10.0 μL chlorobenzene (extraction solvent) and 50 μL acetic anhydride (derivatization reagent) was rapidly injected by syringe in 5.00 mL aqueous sample containing CPs (analytes) and K 2CO 3 (0.5%, w/v). Within a few seconds the analytes derivatized and extracted at the same time. After centrifugation, 0.50 μL of sedimented phase containing enriched analytes was determined by GC-ECD. Some effective parameters on derivatization and extraction, such as extraction and disperser solvent type and their volume, amount of derivatization reagent, derivatization and extraction time, salt addition and amount of K 2CO 3 were studied and optimized. Under the optimum conditions, enrichment factors and recoveries are in the range of 287–906 and 28.7–90.6%, respectively. The calibration graphs are linear in the range of 0.02–400 μg L −1 and limit of detections (LODs) are in the range of 0.010–2.0 μg L −1. The relative standard deviations (RSDs, for 200 μg L −1 of MCPs, 100 μg L −1 of DCPs, 4.00 μg L −1 of TCPs, 2.00 μg L −1 of TeCPs and PCP in water) with and without using internal standard are in the range of 0.6–4.7% ( n = 7) and 1.7–7.1% ( n = 7), respectively. The relative recoveries of well, tap and river water samples which have been spiked with different levels of CPs are 91.6–104.7, 80.8–117.9 and 83.3–101.3%, respectively. The obtained results show that simultaneous DLLME and derivatization combined with GC-ECD is a fast simple method for the determination of CPs in water samples.

Study of different parameters affecting the derivatization of acidic herbicides with trimethylsulfonium hydroxide to make them suitable for gas chromatography analysis

In this study, an orthogonal array design was applied to know the way different parameters affected the derivatization of some herbicides that are commonly applied in the soils. Herbicides formulated as esters have been reported to rapidly hydrolyse, in contact with soil, to their corresponding acids and phenols. What involves is that both forms need to be monitored. Acidic herbicides and phenols cannot be detected by gas chromatography (GC) due to their polarity and low volatility that cause peak asymmetry. Therefore, masking of these polar groups by eliminating the active hydrogen atom with derivatization to their corresponding esters/ethers is needed in order to yield products that possess enhanced volatility and improved GC properties. A lot of derivatization reagents have been proposed but trimethylsulfonium hydroxide (TMSH) was selected due to its easy and quantitative formation of methyl esters/ethers. It was observed that the addition of TMSH promoted not only esterification of acids/phenols but trans-esterification of the original non-hydrolyzed remaining esters to their corresponding methyl ones. As a result, methyl esters/ethers were the final product of both reactions. Different parameters were studied in the statistical design for both TMSH promoted reactions: type of solvent, pH, temperature and time of incubation. The amount of derivatization reagent was calculated to be high enough to ensure the complete derivatization of all compounds present in the sample. The reaction medium was shown as an important factor. The formation of some methyl esters/ethers decreased with increasing time and temperature because trans-esterification, being an equilibrium where the formation of smaller structures is promoted, was not enough shifted. However, the statistical analysis revealed that only the pH of the solution played an important role during the derivatization process. The presence of the anionic form of the acids appeared to be essential for derivatization, being diminished in strong acidic conditions. In addition, pre-heating was shown not to improve derivatization reaction, being easily carried on in the injector port of the GC system.