ABSTRACT
Liquid-phase microextraction is a novel pretreatment technique for biological samples developed on the basis of liquid-phase extraction technology, which is simple, rapid, economical, and environmentally friendly, and has been widely used in the analysis of biological matrix samples such as blood, urine, and saliva. In this paper, we review the basic principles of the main modes of liquid-phase microextraction techniques, i.e., single-drop microextraction, dispersive liquid-liquid microextraction, and hollow-fiber liquid-phase microextraction, and the progress of their applications in biological sample pretreatment by reviewing the literature in the past five years, with a view to providing technical support and reference for sample pretreatment in the fields of in vivo drug analysis, pharmacokinetic studies and new drug development.
ABSTRACT
Abstract Thiazolidinedione, often shortened to TZD or glitazone, helps lower insulin resistance, which is the underlying problem for many people with type 2 diabetes. The two most known glitazones are pioglitazone (PGZ), with the brand name medicine Actos®, and rosiglitazone (RSG), which is Avandia®. This study presented a multivariate optimization in the microextraction procedure employing Fractional Factorial Design (FFD) combined with Desirability Function (DF) to determine TZD and metabolites in biological samples. Microextraction requires several parameters to be optimized; however, most of them still use univariate optimization. Finding optimum conditions by simple response is relatively simple, but the problems, in case of microextractions, are often more complex when it has more responses. For example, changing one factor that promotes one response may suppress the effect of the others. Thus, this multivariate optimization was applied for two bioanalytical methods for determination of TZD and metabolites, one by HPLC and other by CE, both using Hollow Fiber Liquid-Phase Microextraction (HF-LPME). The results establish the optimal values and elucidate how the factors that affect HF-LPME procedure perform in extraction efficiency for TZDs. Additionally, this study demonstrates that DF can be an important tool to optimize microextraction procedures.
Subject(s)
Chromatography, High Pressure Liquid/methods , Thiazolidinediones/adverse effects , Pioglitazone/analogs & derivatives , Methods , Insulin Resistance , Diabetes Mellitus, Type 2/pathology , Rosiglitazone/analogs & derivativesABSTRACT
OBJECTIVE：To establish t he metho d for the content determination of pulegone in Schizonepetae tenuifolia decoction pieces and its compound preparation. METHODS ：Hollow fiber liquid-phase microextraction coupled with HPLC （HF-LPME-HPLC） was adopted. Based on single factor tests ，HF-LPME condition of S. tenuifolia decoction pieces and its compound preparation （taking Compound S. tenuifolia granule as an expample ） was optimized by central composite design-response surface methodology using pulegone enrichment multiple as index ，with the concentration of sample phase solution （NaCl），extraction time and stirring speed as factors. Validation test was conducted. HPLC method was adopted to determine the content of pulegone. The determination was performed on Hypersil C 18 column with mobile phase consisted of methanol- 0.3％ phosphoric acid （gradient elution ）at the flow rate of 1.0 mL/min. The detection wavelength was set at 252 nm，the column temperature was 25 ℃. The sample size was 20 μL. The feasibility of HF-LPME-HPLC method established in this study was validated by using HPLC method stated in the item of S. tenuifolia decoction pieces in 2020 edition of Chinese Pharmacopoeia （part Ⅰ）as reference. RESULTS ：The optimum HF-LPME conditions included n-nonanol as the extraction solvent ，sample phase solution with 11％ NaCl and pH value of 7，stirring speed of 800 r/min，extraction time of 36 min. Results of HPLC methodology investigation showed that linear range of pulegone were 0.05-5 μg/mL（r＝0.999 0）. The limits of detection and quantitation were 0.4 and 1.3 ng/mL，respectively. RSDs of intra-day and inter-day precision were 1.8％-4.0％ and 1.5％-4.1％（n＝3），respectively. RSDs of reproducibility and stability tests （24 h）were all lower than 8％（n＝6）. Average recoveries of S. tenuifolia decoction pieces and Compound S. tenuifolia granule were 102.6％-105.1％ and 97.2％-102.3％，respectively；RSDs were not higher than 4.1％ and 6.2％（n＝3）. The average contents of pulegone in S. tenuifolia decoction pieces determined by pharmacopoeia method and established method were 0.84 mg/g（RSD＝4.3％ ，n＝3）and 0.87 mg/g（RSD＝5.5％ ，n＝3），respectively，with no significant difference （P＞0.05）. CONCLUSIONS ：The established HF-LPME-HPLC method can enrich and concentrate pulegone ， shows strong purification ability and high sensitivity ，and can be used to determine the contents of pulegone in S. tenuifolia decoction pieces and its compound preparation.
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A rapid,accurate,and sensitive analytical method,ultrasonication-assisted spraying based fine droplet formation-liquid phase microextraction-gas chromatography-mass spectrometry (UA-SFDF-LPME-GC-MS),was proposed for the determination of trace amounts of hydroxychloroquine sulfate in human serum,urine,and saliva samples.To determine the best extraction strategy,several liquid and solid phase extraction methods were investigated for their efficiencies in isolation and preconcentration of hydroxychloroquine sulfate from biological matrices.The UA-SFDF-LPME method was determined to be the best extraction method as it was operationally simple and provided accurate results.Variables such as the extraction solvent,spraying number,sodium hydroxide concentration and volume,sample vol-ume,mixing method,and mixing period were optimized for the proposed method using the one-variable-at-a-time approach.In addition,Tukey's method based on a post hoc comparison test was employed to evaluate the significant difference between the parameters inspected.After the optimiza-tion studies,the limit of detection (LOD) and limit of quantification (LOQ) were determined to be 0.7 and 2.4 μg/kg,respectively.The sensitivity of the GC-MS system based on the LOD was enhanced approxi-mately 440-fold when the UA-SFDF-LPME method was employed.Spiking experiments were also con-ducted for the human serum,urine,and saliva samples to determine the applicability and accuracy of the proposed method.Recoveries for the human serum,urine,and saliva samples were found to be in the ranges of 93.9％-101.7％,95.2％-105.0％,and 93.1％-102.3％,respectively.These results were satisfactory and indicated that the hydroxychloroquine sulfate level in the above biological samples could be analyzed using the proposed method.
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Hollow-fiber liquid-phase microextraction (HF-LPME) and electromembrane extraction (EME) are miniaturized extraction techniques, and have been coupled with various analytical instruments for trace analysis of heavy metals, drugs and other organic compounds, in recent years. HF-LPME and EME provide high selectivity, efficient sample cleanup and enrichment, and reduce the consumption of organic sol-vents to a few micro-liters per sample. HF-LPME and EME are compatible with different analytical in-struments for chromatography, electrophoresis, atomic spectroscopy, mass spectrometry, and electrochemical detection. HF-LPME and EME have gained significant popularity during the recent years. This review focuses on hollow fiber based techniques (especially HF-LPME and EME) of heavy metals and pharmaceuticals (published 2017 to May 2019), and their combinations with atomic spectroscopy, UV-VIS spectrophotometry, high performance liquid chromatography, gas chromatography, capillary elec-trophoresis, and voltammetry.
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Objective A new hollow fiber liquid phase microextraction combined with high-performance liquid chromatography was developed to determine the concentration of berberine in rat plasma. Methods Parameters that affect the hollow fiber liquid phase microextraction processes were investigated and optimized. The optimized conditions were pH of donor and acceptor phases 12 and 2.0, respectively; extraction time 20 min; stirring speed 800 rpm; and addition of 10 % (w/v) salt. Under the optimized conditions, the preconcentration factor for berberine was 347. Moreover, a rapid and sensitive method was developed to determine berberine in rat plasma by HPLC. Results The calibration curve for berberine was linear in the range of 10-1000 ng/ml (r2≥0.9992). The limit of quantitation for the analyte was 10 ng/ml (S/N=10). The limit of detection for the analyte was 3.3 ng/ml (S/N=3). The intra-day and inter-day precision, and stability (RSD) were less than 6.3%. The average recovery was 96.7% ± 3.82%, and RSD was 4.82%. Conclusions The method is efficient, green, accurate and repeatable. It can be applied in determination of berberine in rat plasma.
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Objective To develop a method for determination of ultra-trace 2-chlorovinylarsonic acid (CVAOA) in human urine specific to lewisite exposure. Methods The conditions for dispersive liquid-phase microextraction (DLPME) were optimized by orthogonal experiments with results as follows: a mixture of 250 μl methanol (dispersive solvent), 250 μl ethyl acetate (extraction solvent), and 3,4-dimercaptotoluene (DMT) (derivatization reagent, using 1‘100 mole ratio of CVAOA to DMT) was injected into 1 ml urine when pH was adjusted to 1. In the next 60 min, the CVAOA was derivated and the CVAOA-DMT derivative was extracted simultaneously at 90°C. The derivative was then analyzed by gas chromatography/tandem mass spectrometry-select reaction monitoring [GC/ MS/MS(SRM)]. Results The linear calibration extended from 50 pg/ml to 1 μg/ml (r2=0.9999) with the relative standard deviations (RSD) less than 10%. The limit of detection was 18 pg/ml and the limit of quantitation was 56 pg/ml, which was much lower than that of the reported DLPME methods. When detecting human urine samples with low, middle and high spiked concentrations (0.5, 5 and 50 ng/ml) of lewisite, the analysis accuracies ranged from 98.2% to 104% and the RSD ranged from 6.9% to 8.9%. Conclusion The method developed in this study has high specificity and sensitivity as well as good precision and accuracy. It is simple and can be readily applied to the exposed sample analysis.
ABSTRACT
Objective To develop a method for determination of ultra-trace 2-chlorovinylarsonic acid(CVAOA)in human urine specific to lewisite exposure. Methods The conditions for dispersive liquid-phase microextraction(DLPME)were optimized by orthogonal experiments with results as follows:a mixture of 250μl methanol(dispersive solvent),250μl ethyl acetate(extraction sol?vent),and 3,4-dimercaptotoluene(DMT)(derivatization reagent,using 1∶100 mole ratio of CVAOA to DMT)was injected into 1 ml urine when pH was adjusted to 1. In the next 60 min,the CVAOA was derivated and the CVAOA-DMT derivative was extracted simul?taneously at 90℃. The derivative was then analyzed by gas chromatography/tandem mass spectrometry-select reaction monitoring〔GC/MS/MS(SRM)〕. Results The linear calibration extended from 50 pg/ml to 1μg/ml(r2=0.9999)with the relative standard deviations (RSD)less than 10%. The limit of detection was 18 pg/ml and the limit of quantitation was 56 pg/ml,which was much lower than that of the reported DLPME methods. When detecting human urine samples with low,middle and high spiked concentrations(0.5,5 and 50 ng/ml)of lewisite,the analysis accuracies ranged from 98.2%to 104%and the RSD ranged from 6.9%to 8.9%. Conclusion The method developed in this study has high specificity and sensitivity as well as good precision and accuracy. It is s imple and can be readi?ly applied to the exposed sample analysis.
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As drogas facilitadoras de crime (DFC) são uma série de substâncias químicas que permitem o ato sexual e/ou roubo com pouca ou nenhuma resistência da vítima. Benzodiazepínicos, gama-hidroxibutirato (GHB), cetamina e etanol são clássicas DFC, porém outras substâncias também têm sido utilizadas. Devido às diferentes classes de DFC e a necessidade de métodos sensíveis, a determinação dessas substâncias é um desafio aos toxicologistas forenses. A proposta do estudo foi desenvolver métodos analíticos para determinação principais analitos alvos de DFC para benzodiazepínicos, cetamina e GHB em amostras de urina. Esta matriz biológica é considerada uma amostra não-invasiva e apresenta um período de detecção maior que o sangue. A preparação das amostras foi avaliada através de microextração em fase líquida (LPME) e extração líquido-líquido (LLE). A LPME é uma técnica de extração de drogas que utiliza menor quantidade de solventes orgânicos, maior praticidade e possibilidade de obtenção de altos valores de recuperação. Os analitos foram determinados por cromatografia gasosa acoplada à espectrometria de massas (GC-MS). A LPME validada para benzodiazepínicos e seus produtos de biotransformação exigiu uma combinação de solventes e dupla derivatização para atingir a sensibilidade exigida, enquanto o método para determinação de cetamina, norcetamina e deidronorcetamina utilizou óleo essencial de eucalipto como meio extrator, caracterizando-se um procedimento ecologicamente correto com alta sensibilidade. A extração de GHB foi efetiva por LLE com redução da quantidade de solvente e tempo de análise sem o prejuízo na sensibilidade. Em geral, os métodos desenvolvidos neste trabalho são sensíveis e confiáveis para todos os analitos relatados e conclui-se que a LPME é uma técnica de preparo de amostra eficiente, versátil de baixo custo. Estas condições permitem que sua implementação em qualquer laboratório de análises toxicológicas, podendo ser aplicada em situações de DFC ou de qualquer outra natureza
Drug-facilitated crime (DFC) are a series of chemicals that allow the sexual act and/or theft with little or no resistance from the victim. Benzodiazepines, gamma-hydroxybutyrate (GHB) and ketamine and ethanol are considered classic DFC, however other substances were also used as the DFC. Due to the different classes of DFC and the need for sensitive methods, the determination of these substances is a challenge to forensic toxicologists. The purpose of this study was to develop analytical methods for determination of the main target analytes of DFC for benzodiazepines, ketamine and GHB in urine samples. This biological matrix is considered a non-invasive sample and shows a larger window of detection than blood. Sample preparation was assessed using liquid phase microextraction (LPME) and liquid-liquid extraction (LLE). The LPME is a drug extraction technique that uses less organic solvents, greater practicality and possibility of obtaining high recovery values. The analytes were determined by gas chromatography - mass spectrometry (GC-MS). The validated LPME technique for benzodiazepines and their metabolites required a combination of solvents and double derivatization to achieve the required sensitivity, while the ketamine, norketamine and dehydronorketamine method used essential oil of eucalyptus as solvent, characterizing a green chemistry approach with high sensitivity. The extraction of GHB was effective by LLE with a reduced amount of solvent and the analysis time without loss in sensitivity. In general, the methods developed in this work using GC-MS are sensitive and reliable for all analytes reported and LPME technique showed to be an efficient sample preparation, versatile and low cost. These conditions allow LPME implementation in any laboratory of toxicological analysis and it can be applied in situations of DFC or any other kind of analysis
Subject(s)
Laboratory and Fieldwork Analytical Methods/analysis , Urine Specimen Collection/classification , Mass Spectrometry , Chromatography, Gas , Receptors, GABA-A/analysis , Substance-Related Disorders , Forensic Toxicology , Liquid Phase Microextraction/methods , Forensic MedicineABSTRACT
Os antidepressivos pertencem a uma importante classe de medicamentos investigados na toxicologia forense. Em casos de amostras provenientes de cadáveres, o intervalo entre o óbito e a obtenção da espécie biológica pode proporcionar a redistribuição postmortem destes fármacos. Com o objetivo de elucidar esse fenômeno, métodos analíticos foram desenvolvidos e aplicados utilizando sangue total (ST), humor vítreo (HV) e fígado. Para as amostras de ST e HV, o método de extração escolhido e validado foi a microextração em fase líquida (LPME) trifásica. Fibras ocas constituídas de polipropileno, com a extensão de 8 cm cada, foram tratadas com o solvente orgânico dodecano (fase orgânica), resultando em um membrana com permeabilidade seletiva. No lúmen destas fibras, adicionou-se ácido fórmico 0,1 mol/L (fase aceptora). Em frasco de fundo chato com 5 mL de capacidade, pipetou-se 3,5 mL de NaOH 0,1 mol/L (fase doadora) e 0,5 mL de ST ou HV. Ao término da extração, as amostras foram introduzidas no GC-MS, sem a necessidade de reações de derivatização. O estudo com ST contemplou os antidepressivos amitriptilina (AMI), nortriptilina (NTR), imipramina (IMI), desipramine (DES), clomipramina (CLO), desmetilclomipramina (DMC), fluoxetina (FLU) e norfluoxetina (NFL). Os limites de quantificação para estas substâncias ficaram inferiores aos níveis terapêuticos (20 ng/mL). As médias dos coeficientes de variação intradia e interdia foram, respectivamente, de 9,7 e 9,8%. As curvas de calibração apresentaram linearidade entre as concentrações de 20 até 1200 ng/mL. A validação do parâmetro integridade da diluição assegurou a mensuração de quantidades superiores ao limite apresentado na curva de calibração. O método foi aplicado em sete amostras reais postmortem e em apenas um caso foi observada uma diferença significativa (300%) entre os valores quantificados no ST periférico e central. Os antidepressivos tricíclicos AMI, NTR, IMI e DES foram avaliados no HV e o efeito matriz foi detectado para os dois últimos analitos. O método foi otimizado e validado utilizando solução salina adicionada de AMI e NTR. O limite de detecção igual a 5 ng/mL, foi obtido com a redução da voltagem da fonte de íons do espectrômetro de massa para 50 eV. Coeficientes de variação foram inferiores a 15%. Os procedimentos validados foram aplicados em seis amostras reais de HV. A relação encontrada entre os valores obtidos no ST periférico e HV foi de aproximadamente 0,1. A extração acelerada por solvente (ASE) e, posteriormente, a extração em fase sólida (SPE) foram as técnicas de separação dos analitos da matriz fígado. Ao término das citadas extrações, os antidepressivos foram analisados no GC-MS. Para esta matriz sólida, são necessários mais estudos, pois os valores encontrados nos ensaios analíticos estão em desacordo com as diretrizes utilizadas na validação dos métodos
Antidepressants belong to an important class of drugs investigated in forensic toxicology. In cases of samples from corpses, the interval between death and obtaining the biological specimens can provide the postmortem redistribution of these drugs. Aiming to elucidate this phenomenon, analytical methods were developed and applied using whole blood (WB), vitreous humor (VH) and liver. For samples of WB and HV, the extraction method chosen and validated was the three-phase liquid phase microextraction (LPME). Hollow fibers consist of polypropylene, with a length of 8 cm each were treated with dodecane organic solvent (organic phase) resulting in a membrane with selective permeability. Into the lumen of these fibers was added formic acid 0.1 mol/ L (acceptor phase). In the vial containing 3.5 mL of NaOH 0.1 mol / L (donor phase) was spiked 0.5 ml of biological fluids (WB or VH). Subsequently, the samples were injected in GC-MS without derivatization reactions. The study of the ST included antidepressants amitriptyline (AMI), nortriptyline (NTR), imipramine (IMI), desipramine (DES), clomipramine (CLO), desmethylclomipramine (DMC), fluoxetine (FLU) and norfluoxetine (NFL). The quantification limits for these substances were below the therapeutic levels (20 ng / ml). The mean coefficients of variation and separate intradays were respectively 9.7 and 9.8%. The calibration curves showed linearity between concentrations of 20 to 1200 ng / mL. The validation of the integrity of the dilution parameter assured measurement higher than the limit shown in the calibration curve quantities. The method was applied to seven real postmortem samples and in one case a significant difference (300%) between the measured values in the peripheral and central ST was observed. The tricyclic antidepressants AMI, NTR, IMI and DES were evaluated in VH and the matrix effect was detected in the last two analytes. The method was optimized and validated using saline spiked AMI and NTR. The limit of detection (5 ng/ml) was obtained by reducing the voltage of the ion source of the mass spectrometer 50 eV. Coefficients of variation were below 15%. The procedures were validated in six real samples of HV. The relationship found between the values obtained in the peripheral ST and HV was approximately 0.1. Accelerated solvent extraction (ASE) and subsequently the solid phase extraction (SPE) were the techniques of separation of analytes liver matrix. At the end of the cited extractions, antidepressants were analyzed in GC-MS. To this solid tissue, further studies are needed, because the values found in the analytical tests were not in accordance with the guidelines used in the validation of the methods