The monomethyl and dimethyl derivatives of benzo[e]pyrene

Convenient syntheses of the previously unknown complete set of six isomeric monomethyl derivatives of benzo[e]pyrene, 1-, 2-, 3-, 4-, 9- and 10-methylbenzo[e]pyrene, are described. Syntheses of 1-, 2- and 3-methylbenzo[e]pyrene were accomplished through reaction of 7H-benzanthrene (or its 1-Me derivative as appropriate) with 1, 3-bis(dimethylamino)trimethinium perchlorate (or its 1-Me derivative) followed by thermal electrocyclic ring closure accompanied by elimination and aromatization. The earlier claim¹⁶ that the analogous isomeric benzo[a]pyrene derivatives are principal products of reactions of this type is disproven. Synthesis of 3,6- and 4,5-dimethylbenzo[e]pyrene are also described. The structural assignments of all mono- and dimethyl benzo[e] pyrene products are supported by high resolution 270 MHz proton NMR spectra; the chemical shifts and coupling constants of all aromatic protons are fully assigned.     

改进的QuEChERS-液相色谱法检测蔬菜中的苯并(α)芘

采用改进的QuEChERS,对蔬菜样品进行提取、净化,用高效液相色谱仪/荧光检测器检测,建立了蔬菜中苯并(α)芘的测定方法.样品用乙腈提取,PSA+中性Al2O3小柱净化,以10mL正己烷-乙腈(95:5,体积比)洗脱小柱,外标法定量.苯并(α)芘的含量在1.0～20.0μg/kg范围内与峰面积呈良好线性,相关系数(r...     

Sensitive and selective determination of metabolically formed trans-dihydrodiols and phenols of benzo[a]pyrene in water and urine samples by HPLC with amperometric detection

A method has been developed to separate hydroxylated metabolites of the carcinogenic polycyclic aromatic hydrocarbon benzo[a]pyrene, i. e. trans-4,5-, 7,8-, 9,10-dihydrodiol and 1-, 3-, 7-, and 9-phenol, by HPLC with amperometric detection employing an isocratic methanol/water eluent (70:30, v/v) containing 0.5 g/L sulfuric acid and 1 g/L lithium perchlorate. Compared with the usually applied fluorescence (λ_ex = 265 nm, λ_em = 460 nm) and ultraviolet (λ = 265 nm) detection, the amperometric technique is about 2–12 times more sensitive for the determination of all metabolites investigated. The method was applied to the determination of the seven metabolites of benzo[a]pyrene in different water samples and in urine after solid-phase extraction (SPE). The results obtained by HPLC with amperometric detection after SPE enrichment from an aqueous extract of a soil sample and from the urine of a rat intragastrically treated with benzo[a]pyrene agreed well with the values determined with fluorescence and/or UV detection.     

Method development and validation for optimized separation of benzo[a]pyrene-quinone isomers using liquid chromatography-mass spectrometry and chemometric response surface methodology

The successful separation of three benzo[a]pyrene-quinone isomers, two of which were previously unresolved, using liquid chromatography-mass spectrometry (LC-MS) and response surface methodology is presented. Initial efforts centered on chromatographic separation of benzo[a]pyrene-1,6/3,6-quinone peaks evaluated for both resolution and retention time. The mergence of the two parameters was accomplished using the Derringer's desirability function with subsequent optimization by a Box-Behnken response surface design. By implementing the optimal flow rate, column temperature and eluent composition predicted by the validated model, enhanced resolution of the two isomers was achieved in less than 20 min. Calibrations were performed to quantify these isomers and the limits of detection were determined. Optimal model conditions were then used to identify three independent benzo[a]pyrene-quinone isomers produced in the irradiation of a benzo[a]pyrene standard solvated in oxygen-saturated methanol/methylene chloride. This work is not only highly significant to the field of environmental chemistry, but instructive for investigators struggling with the co-elusion of isomeric compounds in their work.     

采用新型固相萃取柱快速测定食用植物油中苯并［a］芘

研究了Bond Elut ENV新型固相萃取柱在食用植物油中苯并[a]芘快速检测中的应用,建立了快速测定食用植物油样品中苯并[a]芘残留量的固相萃取/液相色谱/荧光检测法。样品用正己烷溶解,固相萃取净化,SUPELCOSILTMLC-PAH(25 cm×4.6 mm,5μm)色谱柱分离,以乙腈-水(95∶5)为流动相,荧光检测(λex=297 nm,λem=408 nm),外标法定量。苯并[a]芘的检出限为0.3μg/kg,在1.0～50.0μg/L范围内线性关系良好,相关系数为0.999 6,方法的回收率为79%～102%,相对标准偏差不高于9.4%。该方法准确、实用、简便、快速,在食用植物油的苯并[a]芘残留量检测方面有广泛的应用前景。     

固相萃取-高效液相色谱-荧光法测定方便面和烤肠中的苯并[a]芘

建立了固相萃取-高效液相色谱-荧光法检测方便面和烤肠中苯并[a]芘的方法。采用正己烷作为提取溶剂,经苯并[a]芘专用固相萃取柱HiCapt Benzo富集净化,高效液相色谱-荧光法对样品中苯并[a]芘进行分离分析。苯并[a]芘的质量浓度在0.5~20.0μg/kg范围内与色谱峰面积呈良好的线性关系,相关系数R2为0.9997。方便面和烤肠中苯并[a]芘的加标回收率分别为92.2%~98.3%和95.9%~97.9%,日内和日间相对标准偏差分别为3.34%~5.01%和2.11%~4.07%。与传统方法相比,该方法快速简单、有机溶剂消耗少,在油炸烟熏食品的苯并[a]芘分析中具有较大应用前景。     

Improvement of an automatic HPLC system for nitropolycyclic aromatic hydrocarbons: removal of an interfering peak and increase in the number of analytes.

An automatic HPLC system for analyzing nitropolycyclic aromatic hydrocarbons (NPAHs, nitroarenes) in airborne particulates was previously described (Anal. Chim. Acta, 2001, 445, 20). Some problems with this system were that it generated a peak originating from an ascorbic acid solution that elutes at a retention time close to that of 1,6-dinitropyrene (DNP), and that it was able to analyze only 1,3-, 1,6-, 1,8-DNPs and 1-nitropyrene (I-NP). Here, we describe an improved system that effectively removes the interfering peak by introducing an ODS column just after the pump for the ascorbic acid solution, and which is capable of analyzing several additional compounds (2-, 4-NPs, 2-nitrofluorene. 6-nitrochrysene, 7-nitrobenz[a]anthracene, 3-nitroperylene and 6-nitrobenzo[a]pyrene etc.). The improved sensitivities were achieved by concentrating the compounds in a benzene-ethanol extract from airborne particulates, by increasing the loading time of the sample solution from 20 to 38 min, and by increasing the flow rate of an ascorbic acid solution from 1.3 to 1.8 mL/min.     

Synthesis, chemical properties and mutagenicity of 1,6- and 3,6-dinitrobenzo[a]pyrenes

Nitration of benzo[a]pyrene (BaP) with HNO3 (d = 1.38) produced a mixture of dinitroBaPs (1,6- and 3,6-isomers) and mononitroBaPs (1-, 3- and 6-isomers). Pure 1,6-dinitroBaP and 3,6-dinitroBaP were obtained by the reduction of the dinitroBaPs mixture with NaSH to yield the separable products 1-amino-6-nitroBaP and 3-amino-6-nitroBaP, followed by conversion to dinitroBaPs via the the diazonium salts. The half-wave potentials (E1/2) corresponding to the one-electron reduction of dinitroBaPs were measured and the relationship of these values to the mutagenicity is discussed.     

Phenacenes from Diels-Alder trapping of photogenerated o-xylylenols: phenanthrenes and benzo[e]pyrene bisimide

[structure: see text] The synthesis of phenanthrene and benzo[e]pyrene bisimides, 1 and 2, was accomplished via the Diels-Alder trapping of sterically congested o-xylylenols photochemically generated from 3,6-dibenzoyl-o-xylene and 1,4-dibenzoyl-9,10-dihydroanthracene, respectively. Absorption and emission from 2 are red-shifted from 1 and unsubstituted benzo[e]pyrene. The fluorescence quantum yield for 2 is an order of magnitude lower than that of 1 and comparable to that of the parent benzo[e]pyrene.     

超高效液相色谱-大气压化学电离-三重四极杆质谱联用法快速测定食品中苯并[a]芘

建立了快速检测食品中苯并[a]芘的超高效液相色谱-三重四极杆质谱联用(UPLC-MS/MS)分析方法。样品用正己烷提取后,经分子印迹固相萃取柱净化,以甲醇和水作为流动相进行梯度洗脱,在XBridge BEH C18柱上实现分离,大气压化学电离(APCI)-三重四极杆质谱正离子MRM方式检测,以苯并[a]芘-d12作为内标的稳定同位素稀释法定量。方法的线性范围为0.07~50μg/kg,定量限为0.07μg/kg。平均加标回收率为86%~104%,相对标准偏差为2.3%~14%。该方法灵敏、准确,适用于食品中苯并[a]芘的测定,已应用于实际样品的检查。     

Sensitive and selective determination of metabolically formed trans-dihydrodiols and phenols of benzo[a]pyrene in water and urine samples by HPLC with amperometric detection

A method has been developed to separate hydroxylated metabolites of the carcinogenic polycyclic aromatic hydrocarbon benzo[a]pyrene, i. e. trans-4,5-, 7,8-, 9,10-dihydrodiol and 1-, 3-, 7-, and 9-phenol, by HPLC with amperometric detection employing an isocratic methanol/water eluent (70:30, v/v) containing 0.5 g/L sulfuric acid and 1 g/L lithium perchlorate. Compared with the usually applied fluorescence (λ_ex = 265 nm, λ_em = 460 nm) and ultraviolet (λ = 265 nm) detection, the amperometric technique is about 2–12 times more sensitive for the determination of all metabolites investigated. The method was applied to the determination of the seven metabolites of benzo[a]pyrene in different water samples and in urine after solid-phase extraction (SPE). The results obtained by HPLC with amperometric detection after SPE enrichment from an aqueous extract of a soil sample and from the urine of a rat intragastrically treated with benzo[a]pyrene agreed well with the values determined with fluorescence and/or UV detection. Received: 20 December 1996 / Revised: 10 March 1997 / Accepted: 30 April 1997     

焦炉降尘中多环芳烃的毛细管超临界流体色谱分析

研究了９个多环芳烃混合样品的超临界流体色谱分析条件，并与毛细管气相色谱法做了比较。超临界流体色谱的条件是：柱温１１０℃；程序升压９．０ＭＰａ（５ｍｉｎ）１．４ＭＰａ／ｍｉｎ２８．０ ＭＰａ。各组分保留时间的相对标准偏差为 １．４％～３．０％，定量分析的相对误差为１．４％～６．０％，比毛细管气相色谱法具有明显的优越性。试验了焦炉降尘样品，发现该样品主要由双环和三环的多环芳烃类物质组成。其中萘含量约占８０％。     

Trennung polyzyklisher aromatischer kohlenwasserstoffe durch hochdruckflössigkeitschromatographie: Vergleich einer bestimmung von benzo[a]pyren nach trennung an saäulen mit quervernetztem celluseacetat und einem reversed-phase system

Separation of polycyclic aromatic hydrocarbons by high-pressure liquid chromatography. Comparison of the determination of benzo(a)pyrene with separation on columns of cross-linked cellulose acetate and a reversed-phase system.

The behaviour of a new high-pressure liquid chromatographic support, i.e. a cross-linked cellulose acetate, as selective separation material for polycyclic aromatic hydrocarbons is discussed. The determination of benzo[a]pyrene is described by an example of separating a so-called benzpyrene fraction. The separation of the benzpyrene fraction was possible by combining column systems with aluminium oxide, cross-linked cellulose acetate or a reversed-phase system. By means of a fluore- scence detector 0.1-0.8 ng benzo[a]pyrene could be detected in 5μl injection volume.     

Laser desorption/ionization coupled to tandem mass spectrometry for real-time monitoring of paraquat on the surface of environmental particles

Aerosol mass spectrometry with laser desorption/ionization was investigated as a possible tool for real-time monitoring of the presence of the pesticide paraquat on the surface of airborne soil particles. Laser desorption/ionization of paraquat dication produced only singly charged ions. The most abundant species were [M](+.), [M - H](+), and [M - CH3](+). Operation of the ion trap mass spectrometer in the MS(3) mode allowed the reduction of the signal dependence on laser fluence fluctuations and permitted the detection of the analyte with good sensitivity and high selectivity. The estimated limit of detection in terms of surface coverage was 0.016 monolayers, approximately 1 attomole of paraquat on the surface of a single micron-sized soil particle.     

溶胶-凝胶杂化整体柱修饰及在多环芳烃检测中的应用

利用点击反应对含叠氮基的溶胶-凝胶整体柱进行了表面修饰,制备了C₆-硅胶杂化整体萃取柱。实验以多环芳烃为分析对象,考察了制备和修饰条件对萃取效率的影响,在优化的条件下,新制备的整体柱对萘、菲、芘和苯并[a]芘的萃取富集倍数分别达到95.9、114.2、103.2和57.8。萃取实验的日内和日间精密度(RSD)分别小于5.5%(n=8)和7.3%(n=10)。建立的管内固相微萃取-高效液相色谱检测16种常见多环芳烃方法的检出限(S/N=3)达到0.08~3.72 μg/L,定量限(S/N=10)达到0.26~12.40 μg/L。土壤中多环芳烃分析的加标回收率为82.4%~110.6%, RSD为2.6%~7.9%(n=3)。与美国国家环境保护局检测土壤中多环芳烃的方法比较,结果一致,准确性高。实验表明,该方法萃取效率高,灵敏可靠,操作简便,重现性好,可满足土壤等样品中痕量多环芳烃检测的要求。     

固相萃取-液相色谱-串联质谱法同时测定尿液中9种多环芳烃代谢物

建立了固相萃取-液相色谱-串联质谱同时测定尿中2-羟基萘、1-羟基萘、2-羟基芴、3-羟基菲、1-羟基芘等9种多环芳烃代谢物的液相色谱-串联质谱测定方法。尿样中结合态的多环芳烃代谢物在β-葡萄糖苷酸酶-芳基硫酸酯酶缓冲液(pH 5.0)作用下,于37℃水浴中避光水解4 h后,以C18固相萃取小柱富集、净化,以甲醇洗脱,采用Waters Symmetry C18色谱柱,流动相为乙腈-0.2%氨水(72∶27,V/V)等度淋洗分离后进入质谱测定。在喷雾电压4 kV,毛细管温度300℃下,以3-羟基菲13C为内标,采用SRM模式负离子扫描方式测定,内标法定量。9种多环芳烃代谢物在尿中的线性范围为0.90～100μg/L;相关系数为0.9970～0.9990;回收率为79.0%～119.8%;相对标准偏差为4.3%～12.4%;检出限为0.04～0.90μg/L;结果表明,本方法可用于尿中9种多环芳烃代谢物的测定。     

A selective method for the determination of benzo[a]pyrene in soil using porous graphitic carbon liquid chromatography columns

A back-flushing procedure using porous graphitic carbon (PGC) HPLC columns has been used successfully for the cleanup of soil samples for the determination of benzo[a]pyrene in ppb levels by an ODS-fluorescence HPLC column. The procedure was tested on nine random soil samples taken from an industrial area of the Kingdom of Bahrain. The mean percent recovery from the PGC column was 96% and the average coefficient of variation for the whole method was 5.2%.     

含杯[4]芳烃毛细管固定相的制备与色谱性能

杯芳烃是由对位取代的苯酚在邻位通过亚甲基连接起来的环状化合物,由于具有可调节大小的空腔,不仅能络合无机离子,而且还可络合有机分子,在分析分离方面有极好的应用前景［１,２］．杯芳烃已用于气相色谱［３,４］、离子选择性萃取［５,６］、液相色谱［７,８］和...     

A liquid chromatography–atmospheric pressure photoionization tandem mass spectrometric method for the determination of azaarenes in atmospheric particulate matter

The development, optimization and validation of a liquid chromatography–atmospheric pressure photoionization tandem mass spectrometric (LC–APPI/MS/MS) method for the determination of 15 azaarenes (4-azafluorene, benzo[h] and -[f]quinoline, phenanthridine, acridine, 1-azafluoranthene, 4-azapyrene, benz[a]- and -[c]acridine, -10-azabenzo[a]pyrene, 7,9- and 7,10-dimethylbenz[c]acridine, dibenz[a,j]-, -[c,h] and [a,i]acridine) in airborne particulate matter is described. Each compound was detected and quantified operating in multiple reaction monitoring mode. Extraction of azaarenes was achieved using accelerated solvent extraction (ASE) with dichlormethane/methanol (50/50, v/v). After extraction, no additional clean-up procedure like solid phase or liquid/liquid extraction was necessary. Limits of quantification (S/N × 10) ranged from 0.2 pg/μl to 1.4 pg/μl, matrix dependent recoveries were between 57% and 94%, with relative standard deviations from 8% to 17%. Applicability of the method was demonstrated analyzing 10 samples of particulate matter (PM_2.5) collected in winter 2008. In all samples dimethylbenz[c]acridines as well as dibenzacridines were below the limit of quantification, concentration of the remaining analytes were in the range from 0.002 ng/m³ to 0.356 ng/m³.     

高效液相色谱法测定生活饮用水中的苯并[a]芘

建立高效液相色谱二极管阵列检测器检测生活饮用水苯并[a]芘的测定方法。采用C18反相色谱柱(150mm×4.6 mm,5μm),在流动相为甲醇–水(体积比为90∶10)、流量1.0 mL/min、检测波长295 nm、柱温35℃、进样体积20μL的条件下测定生活饮用水中苯并[a]芘。该方法检出限为6 ng/L,线性范围0～100 ng/mL,加标回收率为88.1%～93.4%,测定结果的相对标准偏差为1.06%(n=9)。该法样品预处理简单,分离度高,分析时间短,适用于生活饮用水中苯并[a]芘的准确定性定量测定。