壬基酚聚氧乙烯醚在油相中的CMCo及相关问题研究

对壬基酚聚氧乙烯醚在油相中的临界胶束浓度(CMC_o)及与之相关的问题进行了研究,并获得了部分CMC_o值.对CMC_o与表面活性剂自身结构的关系进行分析和数学处理后,发现CMC_o与活性物质自身结构间仍为对数关系.同时在对某些具体体系的界面张力随表面活性剂不同而发生的变化进行了详细分析,发现CMC_w和CMC_o是评价表面活性剂性能的有效工具.     

Studying Effect of Typical Nonplanar Cyclic Alcohols (n = 5‐7) on Micellization of Sodium Dodecyl Sulfate (SDS) in Aqueous Solution and Locating Their Solubilization Site in SDS Micelles

Cyclic alcohols (n = 5‐7) are compounds of distinctive nonplanar structure. Effect of the alcohols on micellization of sodium dodecyl sulfate (SDS) in aqueous solution are examined by determining the critical micelle concentration (CMC) by conductometry and the micelle aggregation numbers (N_agg) by fluorometry, respectively. In general, the CMC of SDS decreases with increase in volume of a cyclic alcohol in water and increases further after attaining a minimum value. The N_agg of SDS varies little with small addition of a cyclic alcohol, but decreases when added in sufficient volume. Both the changes of the CMC and N_agg with carbon number in the ring of the alcohols occur irregularly due to their steric reasons and nonplanar nature. The irregularity makes a difference between the cyclic alcohols and their chain counterparts. Based on ¹H NMR chemical shift measurements, the cyclic alcohols are found to be solubilized in the palisade layer in SDS micelles.     

Rapid determination of trace polycyclic aromatic hydrocarbons in particulate matter using accelerated solvent extraction followed by ultra high performance liquid chromatography with fluorescence detection

A method has been developed for the trace analysis of polycyclic aromatic hydrocarbons, which are known as persistent organic pollutants and ubiquitous constituents of fine particulate matter that causes growing airborne pollution. The method, which was especially for samples of airborne particulate matter less than 2.5 μm in diameter, utilized accelerated solvent extraction and ultra high performance liquid chromatography with fluorescence detector. Four principal parameters of accelerated solvent extraction were optimized to obtain maximum extraction efficiency. Using the established synergetic programs of gradient elution and fluorescence wavelength switching, a rapid separation was achieved in 6.56 min with good linearity for 15 polycyclic aromatic hydrocarbons (coefficient of determination above 0.999). The limits of detection ranged from 0.833 to 10.0 pg/m³. The precision of the method expressed as inter‐day relative standard deviation ranged from 0.2 to 1%, which was calculated from nine repetitive measurements of 8.00 μg/L analytes. Average spiked recoveries ranged from 71.6 to 97.7%, with the exception of naphthalene. The rapid, sensitive, and accurate method can meet the pressing needs of health risk assessment and increasingly heavy daily tasks of air quality monitoring.     

Effect of alcohols on the micellar properties in aqueous solution of alkyltrimethylammonium bromides

The effect ofn-butanol,n-propanol, andn-hexanol on the critical micelle concentration (CMC) and degree of ionisation of the micelles of dodecyl-, tetradecyl- and hexadecyltrimethylammonium bromides in aqueous solution has been determined by conductimetric techniques. Increase of the molality of added alcohol over the concentration ranges examined (up to 0.3 mol kg^–1 butanol, 0.07 mol kg^–1 pentanol and 0.025 mol kg^–1 hexanol) caused a progressive decrease of CMC and increase of the degree of ionisation for each surfactant-alcohol system. At a constant molality of added alcohol the degree of ionisation increased with a) an increase of the chain length of the surfactant for each alcohol and b) an increase of the chain length of the alcohol for each surfactant. The distribution of each alcohol between the aqueous and micellar phases and the free energy of solubilization were determined from the change of CMC with molality of added alcohol.     

Quantitation of antioxidants in water samples using ionic liquid dispersive liquid-liquid microextraction followed by high-performance liquid chromatography-ultraviolet detection

A simple and efficient method, ionic liquid-based dispersive liquid-liquid microextraction combined with high-performance liquid chromatography-ultraviolet detection (HPLC-UV), has been applied for the extraction and determination of some antioxidants (Irganox 1010, Irganox 1076 and Irgafos 168) in water samples. The microextraction efficiency factors were investigated and optimized: 1-hexyl-3-methylimidazolium hexafluorophosphate [C(6)MIM][PF(6)] (0.06 g) as extracting solvent, methanol (0.5 mL) as disperser solvent without salt addition. Under the selected conditions, enrichment factors up to 48-fold, limits of detection (LODs) of 5.0-10.0 ng/mL and dynamic linear ranges of 25-1500 ng/mL were obtained. A reasonable repeatability (RSD≤11.8%, n=5) with satisfactory linearity (r(2)≥0.9954) of the results illustrated a good performance of the presented method. The accuracy of the method was tested by the relative recovery experiments on spiked samples, with results ranging from 85 to 118%. Finally, the method was successfully applied for determination of the analytes in several real water samples.     

悬浮固化-分散液液微萃取-液相色谱-串联质谱测定纺织废水中磷系阻燃剂

建立了悬浮固化-分散液液微萃取结合液相色谱-串联质谱测定纺织废水中5种痕量磷系阻燃剂的方法。通过对萃取过程中萃取剂、分散剂的种类与体积、盐浓度、溶液pH值等对萃取效率的影响因素优化,确立了最佳萃取条件。采用了密度小于水的十一烷醇(400μL)为萃取剂,甲醇(300μL)为分散剂,控制溶液pH值在6～9之间,NaCl添加量为2 g,萃取时间为涡旋2 min。在优化的萃取条件下,该方法在2～100μg/L均有良好的线性关系,相关系数大于0.995,除二(2,3-二溴丙基)磷酸酯(BIS)的检出限为5μg/L外,三(2-氯乙基)磷酸酯(TCEP)、三(1,3-二氯-异丙基)磷酸酯(TDCP)、三(1-氮丙啶基)氧化膦(TEPA)和三(2,3-二溴丙基)磷酸酯(TRIS)的检出限均为2μg/L。后整理、染色和印花等实际废水样品加标试验表明,方法的平均回收率为71.6%～114.5%, RSD为2.7%～11.2%(n=6)。对11个样品进行检测,其中3个废水样品检出TCEP与TDCP化合物,含量为2.6～3.4μg/L。本方法简单,快速,灵敏度好且环保绿色,能够对纺织废水中的5种痕量磷系阻燃剂...     

凝固漂浮有机液滴-分散液液微萃取结合高效液相色谱法同时测定地表水中多环芳烃和酞酸酯

多环芳烃和酞酸酯是国际公认的优控污染物,因此准确快速地测定水中多环芳烃和酞酸酯非常重要。凝固漂浮有机液滴-分散液液微萃取(DLLME-SFO)是一种简便、快速、环境友好、灵敏度高的样品前处理技术。采用DLLME-SFO同时测定地表水中多环芳烃和酞酸酯的分析方法鲜有报道。该文采用凝固漂浮有机液滴-分散液液微萃取富集技术,结合高效液相色谱紫外/荧光法,建立了同时测定地表水中16种多环芳烃和6种酞酸酯的分析方法。考察优化了影响萃取效率的主要因素,包括萃取剂的种类和用量、分散剂的种类和用量、萃取时间和离子强度等。优化后的萃取实验条件为:5.0 mL水样,10μL十二醇为萃取溶剂,500μL甲醇为分散溶剂,涡旋振荡时间2 min,氯化钠用量0.2 g。目标化合物经多环芳烃专用色谱柱(SUPELCOSIL^TM LC-PAH, 150 mm×4.6 mm, 5μm)结合乙腈-水梯度洗脱分离,16种多环芳烃除苊烯外采用荧光检测,苊烯和6种酞酸酯采用紫外检测,外标法定量。结果表明,22种目标化合物的基质加标回收率为60.2%～113.5%,相对标准偏差为1.9%～14.3%;多环芳...     

A new high-speed hollow fiber based liquid phase microextraction method using volatile organic solvent for determination of aromatic amines in environmental water samples prior to high-performance liquid chromatography

A new and fast hollow fiber based liquid phase microextraction (HF-LPME) method using volatile organic solvents coupled with high-performance liquid chromatography (HPLC) was developed for determination of aromatic amines in the environmental water samples. Analytes including 3-nitroaniline, 3-chloroaniline and 4-bromoaniline were extracted from 6 mL basic aqueous sample solution (donor phase, NaOH 1 mol L⁻¹) into the thin film of organic solvent that surrounded and impregnated the pores of the polypropylene hollow fiber wall (toluene, 20 μL), then back-extracted into the 6 μL acidified aqueous solution (acceptor phase, HCl 0.5 mol L⁻¹) in the lumen of the two-end sealed hollow fiber. After the extraction, 5 μL of the acceptor phase was withdrawn into the syringe and injected directly into the HPLC system for the analysis. The parameters influencing the extraction efficiency including the kind of organic solvent and its volume, composition of donor and acceptor phases and the volume ratio between them, extraction time, stirring rate, salt addition and the effect of the analyte complexation with 18-crown-6 ether were investigated and optimized. Under the optimal conditions (donor phase: 6 mL of 1 mol L⁻¹ NaOH with 10% NaCl; organic phase: 20 μL of toluene; acceptor phase: 6 μL of 0.5 mol L⁻¹ HCl and 600 m mol L⁻¹ 18-crown-6 ether; pre-extraction and back-extraction times: 75 s and 10 min, respectively; stirring rate: 800 rpm), the obtained EFs were between 259 and 674, dynamic linear ranges were 0.1-1000 μg L⁻¹ (R > 0.9991), and also the limits of detection were in the range of 0.01-0.1 μg L⁻¹. The proposed procedure worked very well for real environmental water samples with microgram per liter level of the analytes, and good relative recoveries (91-102%) were obtained for the spiked sample solutions.     

Green method development approach of superheated water liquid chromatography for separation and trace determination of non-steroidal anti-inflammatory compounds in pharmaceutical and water samples and their extraction

Non-steroidal anti-inflammatory drugs (NSAIDs) are pharmaceutical compounds with anti-inflammatory, analgesic, and antipyretic effects. Herein, a simple and rapid high-temperature liquid chromatography and superheated water chromatography method was developed and validated for the trace determination of NSAID residues of ketoprofen, naproxen, sodium diclofenac, and ibuprofen in water samples. The NSAIDs were separated in less than five minutes using buffered distilled water as the mobile phase and ODS Zirconia RP-C18 column as the stationary phase. Linearity was observed in the van’t Hoff plots of the tested drugs by employing a low acetonitrile percentage (20% ACN) in the mobile phase, without any significant changes in their retention mechanisms. However, nonlinear van’t Hoff plots were obtained for the superheated water chromatography data of the tested drugs because of significant changes in their retention factors, transition stage of the stationary phase, or the mobile phase properties. The limits of detection for ketoprofen, naproxen, sodium diclofenac, and ibuprofen were 14, 2, 4.2, and 32 µg L^?1, respectively, and their limits of quantification were 44, 8, 12, and 98 µg L^?1, respectively. The accuracy and precision parameters were determined for selected drugs, where the relative standard deviations were in the range of ± 0.2179–2.6741%. In addition, these conditions were employed for the removal of NSAIDs from the water samples using carbon nanotubes. The proposed system was applied for the separation and analyses of drugs in water and pharmaceutical samples, and acceptable recoveries of 90.48–98.15% for the water samples and 99.9–100.08% for the pharmaceutical samples were obtained.     

Impurity profile of macitentan in tablet dosage form using a stability-indicating high performance liquid chromatography method and forced degradation study

Macitentan (MAC) is a pulmonary arterial hypertension (PAH) drug marketed as a tablet and often has stability issues in the final dosage form. Quantitative determination of MAC and its associated impurities in tablet dosage form has not been previously reported. This study quantified impurities present in Macitentan tablets using a binary solvent-based gradient elution method using reversed phase-high performance liquid chromatography. The developed method was validated per International Conference on Harmonization (ICH) guidelines and the drug product was subjected to forced degradation studies to evaluate stability. The developed method efficiently separated the drug and impurities (48 min) without interference from solvents, excipients, or other impurities. The developed method met all guidelines in all characteristics with recoveries ranging from 85%-115%, linearity with r² ≥ 0.9966, and substantial robustness. The stability-indicating nature of the method was evaluated using stressed conditions (hydrolysis:1 N HCl at 80℃/15 min; 1 N NaOH at 25℃/45 min; humidity stress (90% relative humidity) at 25℃ for 24 h, oxidation:at 6% (v/v) H₂O₂, 80℃/15 min, thermolysis:at 105℃/16 h and photolysis:UV light at 200 Wh/m²; Fluorescent light at 1.2 million luxh). Forced degradation experiments showed that the developed method was effective for impurity profiling. All stressed samples were assayed and mass balance was>96%. Forced degradation results indicated that MAC tablets were sensitive to hydrolysis (acid and alkali) and thermal conditions. The developed method is suitable for both assay and impurity determination, which is applicable to the pharmaceutical industry.     

Multi-residue method for trace level determination of pharmaceuticals in solid samples using pressurized liquid extraction followed by liquid chromatography/quadrupole-linear ion trap mass spectrometry

A simple and sensitive method for simultaneous analysis of 43 pharmaceutical compounds in sewage sludge and sediment samples was developed and validated. The target compounds were extracted using pressurized liquid extraction (PLE) and then purified and pre-concentrated by solid phase extraction (SPE) using a hydrophilic-lipophilic balanced polymer. PLE extraction was performed on temperature of 100 °C, with methanol/water mixture (1/2, v/v) as extraction solvent. The quantitative analysis was performed by liquid chromatography tandem mass spectrometry using a hybrid triple quadrupole-linear ion trap mass spectrometer (LC-QqLIT-MS). Data acquisition was carried out in selected reaction monitoring (SRM) mode, monitoring two SRM transitions to ensure an accurate identification of target compounds in the samples. Additional identification and confirmation of target compounds were performed using the Information Dependent Acquisition (IDA) function. The method was validated through the estimation of the linearity, sensitivity, repeatability, reproducibility and matrix effects. The internal standard approach was used for quantification because it efficiently corrected matrix effects. Despite the strong matrix interferences, the recoveries were generally higher of 50% in both matrixes and the detection and quantification limits were very low. Beside the very good sensitivity provided by LC-QqLIT-MS, an important characteristic of the method is that all the target compounds can be simultaneously extracted, treated and analysed. Hence, it can be used for routine analysis of pharmaceuticals providing large amount of data. The method was applied for the analysis of pharmaceuticals in river sediment and wastewater sludge from three treatment plants with different treatment properties (i.e. capacity, secondary treatment, quality of influent waters). The analysis showed a widespread occurrence of pharmaceuticals in the sludge matrices.     

Determination of 61 organic pollutants in drinking water by solid phase extraction followed by liquid and gas chromatography coupled to tandem mass spectrometry: an analytical strategy for a routine laboratory

A method for determination of 61 organic pollutants (polycyclic aromatic hydrocarbons and organochlorine, organophosphorous and organonitrogen pesticides) is proposed. It is based on solid phase extraction (SPE) and subsequent analysis of the extract by liquid and gas chromatography coupled to tandem mass spectrometry. Method validation yielded to the following values: limits of quantification, from 0.005 to 0.020?µg?L^?1; trueness, 95% to 113% and reproducibility (as percent relative standard deviation), 2% to 15%. Additionally, the method performed well in various proficiency tests.     

基于SiO_(2)@Fe_(3)O_(4)的磁性纳米材料分离富集谷物中痕量黄曲霉毒素B_(1)北大核心CSCD

将SiO_(2)包覆的Fe_(3)O_(4)磁性纳米材料(SiO_(2)@Fe_(3)O_(4))表面偶联识别黄曲霉毒素B_(1)(AFB_(1))的抗体(Ab),用于特异性分离富集谷物中的AFB_(1),进而与高效液相色谱-串联质谱法(HPLC-MS/MS)结合,用于大米、玉米和小麦中AFB_(1)的高效准确检测。采用微波辅助水热合成法制备得到Fe_(3)O_(4)磁性纳米颗粒,并用100μL正硅酸乙酯(TEOS)对其进行SiO_(2)的包覆,得到SiO_(2)@Fe_(3)O_(4)磁性纳米材料,随后进行抗体的偶联得到Ab-SiO_(2)@Fe_(3)O_(4);以pH=7.4的磷酸盐缓冲液(PBS)作为富集缓冲液,加入8 mg Ab-SiO_(2)@Fe_(3)O_(4),在37℃下反应10 min进行AFB_(1)的分离富集,随后采用甘氨酸-盐酸(Gly-HCl)缓冲液对Ab-SiO_(2)@Fe_(3)O_(4)分离富集的AFB_(1)进行洗涤,将洗涤液氮吹后复溶,采用高效液相色谱-串联质谱法检测。在最佳条件下,方法检测AFB_(1)的线性范围为2~50μg/L,相关系数(R^(2))>0.99,检出限为0.04μg/kg,定量限为0.13μg/kg。在4个不同加标水平下,AFB_(1)在3种谷物基质中的加标回收率为76.21%~92.85%,RSD≤5.29%。大米、玉米和小麦等实际谷物样品中AFB_(1)的测定结果显示,在1个小麦样品和2个玉米样品中检出AFB1,其含量分别为0.38、0.13和0.47μg/kg,其他样品中并未发现AFB_(1)。方法将磁性纳米材料与HPLC-MS/MS相结合,实现了AFB_(1)的高效分离富集,富集材料成本低廉,储存性能好,在30 min内即可完成前处理过程,可在较短的时间内实现大批量样品的实际分析,在谷物中真菌毒素的检测方面具有良好的应用前景。     

Simple, rapid, and sensitive determination of beta-blockers in environmental water using dispersive liquid-liquid microextraction followed by liquid chromatography with fluorescence detection

A novel method, dispersive liquid-liquid microextraction combined with liquid chromatography-fluorescence detection is proposed for the determination of three beta-blockers (metoprolol, bisoprolol, and betaxolol) in ground water, river water, and bottled mineral water. Some important parameters, such as the kind and volume of extraction and dispersive solvents, extraction time, pH, and salt effect were investigated and optimized. In the method, a suitable mixture of extraction solvent (60 μL carbon tetrachloride) and dispersive solvent (1 mL acetonitrile) were injected into the aqueous samples (5.00 mL) and the cloudy solution was observed. After centrifugation, the enriched analytes in the bottom CCl(4) phase were determined by liquid chromatography with fluorescence detection. Under the optimum conditions, the enrichment factors (EFs) for metoprolol, bisoprolol, and betaxolol were 180, 190, and 182, and the limits of detection (LODs) were 1.8, 1.4, and 1.0 ng L(-1) , respectively. A good linear relationship between the peak area and the concentration of analytes was obtained in the range of 3-150 ng L(-1) . The relative standard deviations (RSDs) for the extraction of 10 ng L(-1) of beta-blockers were in the range of 4.6-5.7% (n = 5). Compared with other methods, dispersive liquid-liquid microextraction is a very simple, rapid, sensitive (low limit of detection), and economical (only 1.06 mL volume of organic solvent) method, which is in compliance with the requirements of green analytical methodologies.     

中空纤维液相微萃取-超高效液相色谱-串联质谱法测定儿童玩具中6种致敏香豆素类化合物

建立了超高效液相色谱-串联质谱测定儿童玩具中6种致敏香豆素类化合物(香豆素、7-甲基香豆素、7-甲氧基香豆素、7-乙氧基-4-甲基香豆素、4,6-二甲基-8-叔丁基香豆素和六氢香豆素)的分析方法。样品前处理采用中空纤维液相微萃取技术,优化后的萃取实验条件为:萃取剂正辛醇,搅拌速度700 r/min,萃取时间50 min,氯化钠加入量0.7 g。萃取液经ACQUITY UPLC BEH Phenyl色谱柱(150 mm×2.1 mm,1.7μm)分离,目标化合物在电喷雾离子源正离子模式下电离,采用多反应监测模式进行定性定量分析。结果表明,6种致敏香豆素类化合物的定量限为2μg/kg(7-乙氧基-4-甲基香豆素、4,6-二甲基-8-叔丁基香豆素)或10μg/kg(香豆素、六氢香豆素、7-甲基香豆素、7-甲氧基香豆素),在10~120μg/kg范围内不同加标水平下的平均回收率为70.8%~118.9%,相对标准偏差为0.19%~16.34%(n=6)。该法准确、灵敏、可靠,适用于玩具产品的实际检验工作和产品质量控制。     

高效液相色谱-荧光检测法同时测定体外循环下狗血浆中的阿曲库铵和劳丹碱

建立了测定体外循环下狗血浆中阿曲库铵及其代谢产物劳丹碱的高效液相色谱-荧光检测(HPLC-FLD)分析方法。使用Agilent Eclipse Plus C18色谱柱分离,以0.03 mol/L磷酸氢二钾(pH 5.0)-乙腈(72:28, v/v)为流动相,流速1.0 mL/min。以维拉帕米为内标,样品经二氯甲烷萃取、浓缩后以流动相溶解进样,荧光检测的激发波长和发射波长分别为240和320 nm。结果表明,阿曲库铵和劳丹碱分别在25~5000 μ g/L和25~6000 μ g/L范围内线性关系良好(r=0.9990和r=0.9984);方法回收率在92.1%~109.5%之间;检出限分别为3 μ g/L和1 μ g/L;日内和日间精密度(以RSD计)均小于10%;稳定性试验结果显示样品在不同存储条件下的稳定性良好。该方法选择性好,灵敏度高,结果准确,重现性好,可用于阿曲库铵和劳丹碱的血药浓度测定及其药代动力学研究。     

低温冷冻及分散固相萃取净化-超高效液相色谱-串联质谱法测定植物油中104种农药残留

建立了适用于植物油中104种农药残留的检测方法。通过液液萃取(LLE)提取目标化合物,再借助离心、冷冻和分散固相萃取(D-SPE)净化手段,依托超高效液相色谱-串联质谱测定。以回收率和共提取物为衡量指标,着重优化了6种提取方式、不同冷冻时间及PSA(primary secondary amine)、GCB(graphite carbon black)和C18这3种不同固相萃取填料不同组合的效果。在0.01、0.02和0.05 mg/kg水平的平均添加回收率为55%~121%, RSD为0.47%~19.2%, 80%的目标物的定量限可达到1 μg/kg,低于我国相关标准限量,能够满足多种农药残留同时分析的要求。该方法步骤简便、可靠、稳定,可应用于进口植物油中多种农药残留的快速检测与确证的日常检测工作中,具有一定的推广价值。     

液液萃取-场放大进样-毛细管电泳非接触式电导分离检测酱油中的安赛蜜

采用场放大进样(FASI)-毛细管电泳非接触式电导检测法(CE-C⁴D),结合液液萃取(LLE)的样品净化预处理技术,分离检测了酱油中人工合成甜味剂安赛蜜。酱油样品经酸化后,用乙酸乙酯作为萃取剂,成功地消除了酱油中含有的大量无机盐等复杂基体对微量安赛蜜的干扰。实验对影响LLE萃取效率和FASI-CE-C⁴D分离检测的关键因素进行了讨论,特别是对样品净化前处理过程中萃取剂及用量、样品酸化pH值、萃取时间、萃取温度等条件进行了优化。结果表明,酱油中的安赛蜜可获得良好分离和灵敏检测,检出限和定量限分别为0.15 mg/kg和0.48 mg/kg。对市售酱油样品进行安赛蜜的加标回收测定,得到加标回收率为92.3%～108.1%,相对标准偏差<8.0%。该法具有简单快速、灵敏高效、分析成本低的优点,能满足酱油中安赛蜜的分析检测要求。     

应用二极管阵列串联荧光检测-高效液相色谱技术快速测定玩具材料中蒽油的4种成分

采用二极管阵列串联荧光检测-高效液相色谱法对玩具材料中蒽油的4种主要成分蒽、菲、芘、荧蒽进行了检测。样品用正己烷-丙酮溶液超声提取,硅胶小柱净化。方法的荧光检测线性范围为0.5～1000 μg/L,二极管阵列检测线性范围为0.5～1000 mg/L。加标回收、精密度试验表明4种成分的回收率为70.0%～120%,精密度为0.7%～8.8%。蒽、菲、芘、荧蒽的检出限分别为0.1、0.1、0.2、0.3 μg/L,定量限分别为0.4、0.2、0.5、0.8 μg/L。方法具有灵敏度高、检出限低的特点,适用于玩具材料中蒽油4种成分的快速定性、定量检测。