分散固相萃取-高效液相色谱法测定水果中三氯生及三氯卡班

目的建立分散固相萃取-高效液相色谱法测定水果中三氯生及三氯卡班残留的新方法。方法样品采用乙腈溶液涡旋超声提取后,加入十八烷基键合硅胶吸附剂(C18)作为分散固相萃取净化剂进行净化(200mg),用高效液相色谱法在278 nm处测定,采用PICKERING C8色谱柱(4.6 mm×250 mm i.d.,5μm),以甲醇:水(78:22,V:V)的溶液为流动相等度洗脱,流速1.2 m L/min。结果在最优检测条件下,各目标化合物的加标回收率为72.9%~104.4%,相对标准偏差在2.1%~9.1%之间。三氯生及三氯卡班的检出限分别为0.05和0.02 mg/kg,定量限分别为0.15和0.06 mg/kg。结论该方法分析快速、简便,适用于水果中三氯生及三氯卡班的测定。     

基于固相萃取-液相色谱-串联质谱法的纺织品中三氯生和三氯卡班的测定

采用固相萃取-液相色谱-串联质谱技术(SPE-LC-MS/MS)建立了同时测定纺织品中三氯生和三氯卡班的分析方法。样品用二氯甲烷超声提取,C18固相萃取净化后分析。串联质谱在多反应监测(MRM)模式下检测目标分析物,以保留时间和特征离子对(母离子和碎片离子)信息比较进行定性和定量分析。三氯生和三氯卡班的线性范围分别为1.0~50.0 ng/mL、0.25~50.0 ng/mL。方法的定量限为1.0和0.25 μg/kg,平均回收率为84.5% ~ 108.2 %,相对标准偏差小于8.1 %。实验结果表明该方法准确、灵敏,可用于纺织品中三氯生和三氯卡班的分析测定。     

Identification of volatile compounds in soymilk using solid-phase microextraction-gas chromatography

Headspace solid-phase microextraction (HS-SPME) gas chromatography was used to analyze volatile compounds in soymilk. The effect of incubation temperature (30–70 °C) and time (5–60 min), sample volume (0.5–5 ml), and type of SPME fiber (65 μm CWAX–DVB, 70 μm PDMS–DVB and 85 μm CAR–PDMS) were studied. All the factors markedly affected sensitivity and selectivity. Among the three fibers tested, the CAR–PDMS fiber had greater sensitivity to a more diverse range of volatile compounds, followed by PDMS–DVB and CWAX–DVB fibers using both soymilk and water with added volatiles as a matrix. SPME optimization conducted using a water matrix with added known soy volatiles, showed the following conditions to be optimal for selectivity and sensitivity: incubation temperature of 40 °C, incubation time of 20 min, and sample volume of 5 ml (for volatile compound concentration of ∼25 ppm). The selected conditions were used for the analysis of volatiles in six commercial soymilk samples. A total of 30 volatile compounds were identified. The results showed significant differences in the total volatiles of the soymilk products. The repeatability of measurements of total volatiles compounds of soymilk was ∼5.4% for four replicate analyses. Similar volatile compounds were present in all the samples analyzed but at different concentrations. The method proposed is simple and can be used to measure both hexanal and/or total volatiles in soymilk samples.     

Characterization of rum using solid-phase microextraction with gas chromatography–mass spectrometry

Headspace solid-phase microextraction was used to extract and analyze volatile compounds in different aged rums. The interference of ethanol was resolved with a dilution of the sample at 12% v/v. The extraction procedure, using a 100 μm PDMS fibre with 35 min at 30 °C, permitted the isolation of a large quantity of volatile compounds. One hundred and eighty-four volatile compounds were identified, including 64 esters, 47 benzenic compounds, 16 terpenoids, 14 alcohols, 10 acetals, 9 aldehydes, 6 phenols, 6 ketones, 6 furans, 3 acids and 3 benzopyrans.     

Molecularly imprinted solid-phase extraction combined with high-performance liquid chromatography for analysis of trace olaquindox residues in chick feeds

BACKGROUND: Olaquindox, one of the antimicrobial growth accelerants, is usually used as a feed additive in livestock production to improve feed efficiency. Due to health concerns over possible carcinogenic, mutagenic and photoallergenic effects of olaquindox on animals, the development of a simple, rapid and sensitive analytical method for determination of olaquindox is crucial and necessary. RESULTS: In this paper, a novel and hydrophilic functionalised material of olaquindox‐imprinted polymer was synthesised in aqueous solution by a surface molecular imprinting in combination with a sol–gel process. This imprinted material was characterised by Fourier transform infrared, scanning electron microscopy, and static and kinetic adsorption experiments, and results showed that it had good recognition and selective ability, and fast adsorption‐desorption dynamics for olaquindox. Applying the prepared material as sorbent, a method of molecularly imprinted solid‐phase extraction (MISPE) for separation and analysis of olaquindox residues in feeds coupled with HPLC was presented. Under the selected MISPE condition, the detection limit (S/N = 3) for olaquindox was 68.0 ng L^?1, the RSD for five replicate extractions of 50 µg L^?1 olaquindox was 9.8%. The blank chick feed samples spiked with olaquindox at 0.0025 and 0.010 mg g^?1 levels were extracted and determined by the developed method, with recoveries ranging from 90% to 96%. CONCLUSION: This method was applied for enrichment and analysis of olaquindox in animal feed samples with good accuracy and repeatability. This study will provide a sensitive and fast method for the monitoring of olaquindox residues in foods. Copyright © 2011 Society of Chemical Industry     

固相萃取串联高效液相色谱检测动物源性食品中甲巯咪唑残留

以动物源性食品中抗甲亢药物甲巯咪唑为研究对象,采用Cleanert S C18固相萃取柱对复杂动物源性食品进行基质净化,对上样溶剂、洗杂液、洗脱液等试验参数进行优化,建立固相萃取净化富集与高效液相色谱联用技术,实现对猪肾、猪肝、猪肉样品中的痕量甲巯咪唑准确、灵敏检测。在最优试验条件下,在3个添加浓度的猪肾、猪肝、猪肉样品中,分析物甲巯咪唑的回收率均大于85%,相对标准偏差(RSD,n=3)均小于5%,对3种样品中最低检出限(S/N=3)和最低定量限(S/N=10)分别为:猪肾0.59,1.97μg/kg;猪肝0.54,1.80μg/kg;猪肉0.49,1.63μg/kg。所建立的检测方法具有较高的准确度和灵敏度,可以满足对实际样品中甲巯咪唑的分析检测。     

Selective trace analysis of sulfonylurea herbicides in water and soil samples based on solid-phase extraction using a molecularly imprinted polymer

A molecularly imprinted polymer (MIP) was synthesized using the herbicide metsulfuron-methyl (MSM) as a template, 2-(trifluoromethyl)acrylic acid as a functional monomer, divinylbenzene as a cross-linker, and dichloromethane as a porogen. This polymer was used as a solid-phase extraction material for the quantitative enrichment of five sulfonylureas (nicosulfuron, thifensulfuron-methyl, metsulfuron-methyl, sulfometuron-methyl, and chlorsulfuron) in natural water and soil samples and off-line coupled to a reversed-phase HPLC/diode array detection (HPLC/DAD). Washing solvent was optimized in terms of kind and volume for removing the matrix constituents nonspecifically adsorbed on the MIP. It has been shown that the nonspecific binding ability of the sulfonylureas to the polymer largely increased along with increasing the concentration of Ca2+ ions in the water sample, whereas complexation of divalent ions with EDTA eliminated this interference completely. The stability of MIP was tested by consecutive percolation of water sample, and it was shown that the performance of the MIP did not vary even after 200 enrichment and desorption cycles. Recoveries of the five sulfonylureas extracted from 1 L of tap water and surface water samples such as river water and rainwater at a 50 ng/L spike level were not lower than 96%. The recoveries of sulfonylureas extracted from 10-g soil sample at the 50 microg/kg level were in the range of 71-139%. Depending on the particular compound, the limit of detection varied from 2 to 14 ng/L in water and from 5 to 12 microg/kg in soil samples. The MIP was also compared with a commercially available C-18 column and an immunoaffinity support with encapsulated polyclonal anti-MSM antibodies in sol-gel glass.     

新型固相萃取-高效液相色谱检测饮用水中的 邻苯二甲酸脂类物质

目的建立基于新型高效的样品前处理技术即固相萃取-高效液相色谱联用技术同时检测饮用水中七种邻苯二甲酸酯类物质的方法。方法以3-氨基丙基三乙氧基硅烷作为功能单体,四乙氧基硅烷作为交联体,并加入醋酸,合成新型的高选择性材料,并用作为固相萃取材料,吸附七种邻苯二甲酸脂类物质。结果高效液相色谱等度分析方法的最佳检测条件为:流动相为乙腈和水(96:4,V:V);运行时间20 min;检测波长为230 nm;流速1.0 m L/min;柱温30℃;进样量20μL。目标化合物线性范围较宽,其中DMP、DBP、DIDP为0.5~100 mg/L,DCHP、BBP、DEHP为0.5~25 mg/L,DEP为0.5~10 mg/L;该方法对7种目标化合物的检测限在0.18μg/L~1.86μg/L范围内,6次重复实验精密度在1.18%~5.20%之间,标准添加回收率在63.5%~108.4%之间。结论该方法可以用于饮用水中苯二甲酸脂类物质的定量检测。     

Determination of patulin in apple juice using magnetic solid-phase extraction coupled with high-performance liquid chromatography

ABSTRACT

An efficient magnetic sorbent consisting of benzofuran-2-carboxylic acid-loaded magnetic nanocomposite was successfully synthesised for pre-concentration of patulin from apple juice. The prepared magnetic nanocomposite was characterised by scanning electron microscopy, transmission electron microscopy and Fourier-transform infrared spectroscopy. Determination of enriched patulin was performed by high-performance liquid chromatography. The best adsorption conditions were 40 mg of sorbent, 50 ml of apple juice sample, pH 5, ambient temperature and 25 min; the elution conditions were 500 μl methanol, pH 5, ambient temperature, and 4 min. Under optimised conditions, pre-concentration factor was 100, linearity range was 1–400 μg l^–1 of patulin, limit of detection was 0.15 μg l^–1 and limit of quantification was 0.5 μg l^–1. When samples were determined 20 times, the recovery was 93.9–102.6% and the relative standard deviation was below 5.3%. In terms of proposed procedure, the developed method was successfully applied for patulin detection in apple juice samples.     

固相萃取净化-气相色谱法检测人乳中 持久性有机氯农药

目的 建立母乳中有机氯农药六六六和滴滴涕的检测方法, 并对北京、兰州和杭州三个地区的蓄积水平现状进行分析。方法 母乳样品用乙腈提取, 经过酸化的硅胶固相萃取柱净化, 浓缩后, 采用气相色谱仪检测。结果 8种农药的线性范围在5~200 ng/mL, 相关系数0.9955~0.9994, 定量限均小于2.6 μg/kg, 平均回收率在70%~122%, 相对标准偏差在3.91%~10.77%。结论 本方法结合磺化法和固相萃取法, 能有效去除基质中的杂质。通过方法学验证证明, 本方法操作简单、精确、快速, 适用于母乳中有机氯的检测。随着六六六、滴滴涕等持久性有机氯农药的禁用或严格限用, 母乳中持久性有机氯农药的蓄积水平明显降低。     

Analysis of triclocarban in aquatic samples by liquid chromatography electrospray ionization mass spectrometry

Triclocarban, N-(4-chlorophenyl)-N'-(3,4-dichlorophenyl)urea, is a polychlorinated phenyl urea pesticide, marketed under the trademark TCC and used primarily as an antibacterial additive in personal care products. Despite its extensive use over several decades, environmental occurrence data on TCC are scarce. This is due in part to a lack of analytical techniques offering the desired sensitivity, selectivity, affordability, and ease of use. This need is addressed here by introducing a liquid chromatography electrospray ionization mass spectrometry (LC/ESI/MS) method allowing for the determination of TCC concentrations in aquatic environments at the ng/L level. TCC was concentrated from aqueous samples by solid-phase extraction, separated from interferences on a C18 column by either isocratic or gradient elution, and detected and identified in negative ESI mode by selectively monitoring the (M - H)- base peak (m/z 313) and its 37Cl-containing isotopes (m/z 315, 317) that served as reference ions. Particulates contained in aquatic samples were extracted and analyzed separately. Accurate quantification was achieved using stable isotopes of TCC and triclosan as internal standards. Addition of 10 mM acetic acid to the mobile phase yielded acetic acid adducts ([M - H + 60]-) that were successfully exploited to boost method sensitivity and selectivity, especially when analyzing challenging environmental matrixes. Method detection limits were matrix dependent, ranging from 3 to 50 ng/L. In 36 grab samples obtained from the Greater Baltimore area, TCC was detected in river water and wastewater at concentrations of up to 5600 and 6750 ng/L, respectively. Raw and finished drinking water did not contain detectable quantities of the pesticide (<3 ng/L). In conclusion, the new LC/ESI/MS method was applied successfully to collect environmental occurrence data on TCC in U.S. water resources. Study results suggest that the bacteriostat and pesticide is a frequent but currently underreported contaminant whose environmental fate and behavior deserve further scrutiny.     

Detection of heavy metal ions in drinking water using a high-resolution differential surface plasmon resonance sensor

We have built a high-resolution differential surface plasmon resonance (SPR) sensor for heavy metal ion detection. The sensor surface is divided into a reference and sensing areas, and the difference in the SPR angles from the two areas is detected with a quadrant cell photodetector as a differential signal. In the presence of metal ions, the differential signal changes due to specific binding of the metal ions onto the sensing area coated with properly selected peptides, which provides an accurate real-time measurement and quantification of the metal ions. Selective detection of Cu2+ and Ni2+ in the ppt-ppb range was achieved by coating the sensing surface with peptides NH2-Gly-Gly-His-COOH and NH2-(His)6-COOH. Cu2+ in drinking water was tested using this sensor.     

Quantitative determination of formaldehyde in cosmetics using combined headspace–solid-phase microextraction chromatography

The objective of this research was the application of headspace (HS)–solid-phase microextraction (SPME) for quantitation of formaldehyde present in raw materials and cosmetic formulations. The formaldehyde was derivatized in situ first with pentafluorophenylhydrazine (PFPH), to form a derivative hydrazone. The hydrozone was adsorbed on a SPME fiber during headspace extraction under controlled conditions (temperature, volume, etc.). After the adsorption step, the SPME fiber was directly transferred into the chromatography (GC) injection port, in which the analytes were thermally desorbed. Deuterated acetone is regarded as an internal standard (IS) in order to quantitate the formaldehyde content. For the experiment, chromatograph equipped with a flame ionization detector (GC/FID) was employed. A gas chromatograph/mass spectrometer (GC/MS) was used for the qualitative confirmation of results in this work.     

固相分散萃取-液相色谱法测定番茄酱中2-萘酚

采用固相分散萃取-高效液相色谱法测定番茄酱中的2-萘酚。无水硫酸钠作分散剂、乙腈作萃取剂,考察了2,4-二氯苯氧乙酸存在时的干扰情况。色谱条件:TOSOHC18色谱柱;甲醇-水(体积比50∶50)为流动相;流速:1.0 mL/min;检测波长:230 nm。2-萘酚在0.005μg/mL～2.00μg/mL范围内线性良好,方法检出限为1μg/g,平均回收率为75.0%,相对标准偏差为3.0%。     

Mo(Ⅵ)-HMPF-CTMAB光度法测定食品中微量钼

研究了三元配合物Mo(Ⅵ)-2-羟基-3-甲氧基苯基荧光酮(HMPF)-CTMAB的显色条件.最大吸收波长λmax=525.00nm,试剂最大吸收波长为λmax=465.00nm,对比度60nm,ε525=1.30×105L·moL-1·cm-1,钼的浓度0～15μg/25mL,服从比尔定律,该体系选择性好、方法简便、快速,用于食品中微量钼的测定,结果令人满意.     

液-液-液微萃取与高效液相色谱联用法测定猪尿样中的盐酸克伦特罗

建立液-液-液微萃取与高效液相色谱联用技术测定猪尿中盐酸克伦特罗的方法.考察萃取时间、料液pH和搅拌速度的影响,最佳萃取条件为:萃取溶剂为200μL苯,接受相为2.0μL,0.2 mol/L HC1,搅拌速度为240 r/min,萃取时间为30 min.在该条件下,获得了高的富集因子.方法的线性范围为:0.025～5μg/mL;检出限为0.025μg/mL;平均回收率介于95.7%～101.3%(n=6)之间,相对标准偏差小于4.4%.该方法萃取效率高,有机溶剂消耗少,是一种有效、灵敏的测定猪尿样中盐酸克伦特罗方法.     

Detection of oligosaccharides in sugar products using planar chromatography

Oligosaccharides, and in particular raffinose and kestoses, are of great importance not only in the field of cane and beet processing but also in respect of the analyses of a number of agricultural raw materials and trade products. The authors judge it to be useful to have at one's disposal a simple and reliable analytical technique to be used for the detection of oligosaccharides in different materials. Modern planar chromatography can be utilized, bearing in mind that HPTLC (high performance thin layer chromatography) plates, Automated Multiple Development, completely automated elution systems, sample positioning and spots detection apparatuses, are available. Details on the analytical methodology adopted for molasses and other sugar products are presented and discussed also giving statistical data about its accuracy and precision. Some examples of practical application of the proposed methodology are described.     

改进的石墨烯分散固相萃取-液相色谱-串联质谱法测定茶叶中15种氨基甲酸酯类农药的残留量

目的以石墨烯为吸附剂,建立分散固相萃取-液相色谱-串联质谱法测定茶叶中多种氨基甲酸酯类农药残留量。方法样品采用水浸泡、乙腈提取,石墨烯作为吸附剂祛除杂质后,液相色谱-串联质谱仪测定,外标法定量。结果 15种氨基甲酸酯类农药在0.001~0.02μg/mL范围内线性良好,相关系数均大于0.990,且定量限均可达到0.01 mg/kg。空白样品在0.01、0.02和0.10 mg/kg 3个添加水平下,回收率范围为61%~106%,相对标准偏差为4.6%~13%。结论本方法操作简便、快速、成本较低,适用于茶叶中氨基甲酸酯类农药的检测。     

Determination of glyphosate,AMPA, and glufosinate in honey by online solid-phase extraction-liquid chromatography-tandem mass spectrometry

A simple method was developed for the simultaneous determination of glyphosate, its main degradation product (aminomethylphosphonic acid), and glufosinate in honey. Aqueous honey solutions were derivatised offline prior to direct analysis of the target analytes using online solid-phase extraction coupled to liquid chromatography-tandem mass spectrometry. Using the developed procedure, accuracies ranging from 95.2% to 105.3% were observed for all analytes at fortification levels of 5, 50, and 150 μg kg^?1 with intra-day precisions ranging from 1.6% to 7.2%. The limit of quantitation (LOQ) was 1 μg kg^?1 for each analyte. Two hundred honey samples were analysed for the three analytes with AMPA and glyphosate being most frequently detected (99.0% and 98.5% of samples tested, respectively). The concentrations of glyphosate were found to range from <1 to 49.8 μg kg^?1 while those of its degradation product ranged from <1 to 50.1 μg kg^?1. The ratio of glyphosate to AMPA was found to vary significantly amongst the samples where both analytes were present above the LOQ. Glufosinate was detected in 125 of 200 samples up to a maximum concentration of 33.0 μg kg^?1.     

Co-occurrence of triclocarban and triclosan in U.S. water resources

Triclocarban (TCC) and triclosan (TCS) are antimicrobial additives in personal care products. Whereas TCS has been studied extensively, the environmental fate of TCC remains largely unknown. To address this data gap, we performed quantitative structure-activity relationship (QSAR) analyses that suggested a propensity of TCC to persist in various environmental compartments with predicted half-lives ranging from 0.75 days in air to 540 days in sediment. Moreover, concentrations of both antimicrobials were measured in 42 environmental samples from the Greater Baltimore region using a combination of solid-phase extraction, liquid chromatography/mass spectrometry, and isotope dilution. The co-occurrence of TCC and TCS was observed, owing to similar properties, usage, disposal, and environmental half-lives. A linear empirical correlation (R2 = 0.9882) fit the log-log-transformed data from diverse aquatic media and spanned 5 orders of magnitude in concentration. Occurrences of TCC predicted for 85 U.S. streams were statistically indistinguishable from experimental regional data (alpha < or = 0.05). Annual loading of antimicrobials to water resources probably is dominated by activated sludge treatment plants (39-67%), followed by trickling filters (31-54%) and combined and sanitary sewer overflows (2-7% and <0.2%, respectively). Study results suggest that TCC is a previously unrecognized contaminant of U.S. water resources nationwide, likely ranking in the top 10 in occurrence rate and in the top 20 in maximum concentration among 96 organic pollutants considered. The magnitude and frequency of TCC contamination (regional, 6750 ng/L, 68%; predicted nationwide for 1999--2000, 1150 ng/L, 60%) were markedly higher than non-peer-reviewed numbers (240 ng/L, 30%, U.S.) currently used by the U.S. Environmental Protection Agency for evaluating TCC's ecological and human health risks.