纺织品中19种含氯苯酚的气相色谱-质谱联用测定及其迁移行为

建立了气相色谱-质谱联用(GC-MS)同时测定纺织品中19种残留含氯苯酚的分析方法。以棉贴衬纺织品为基底材料,采用0.1 mol/L K_2CO_3溶液作为萃取液及衍生化介质,乙酸酐乙酰化,正己烷萃取后进行GC-MS测定,采用选择离子监测进行确证,外标法定量。检出限为2μg/kg,线性范围为0.0004~1.0 mg/L,线性相关系数R~2大于0.999,加标回收率为88.6%~107.6%,相对标准偏差(RSDs,n=7)为1.8%~7.6%,方法可满足纺织品及其制品中19种含氯苯酚类物质的同时检测需求。研究了棉纺织品中含氯苯酚的迁移行为,表明纺织品表面涂层性质、厚度等均对此迁移行为产生一定的影响。     

高效液相色谱-质谱联用法测定纺织品中的含氯苯酚

建立了高效液相色谱-质谱联用法检测纺织品中五氯苯酚(PCP)、四氯苯酚(TeCP)。选用ZORBAX XDB-C18柱(50 mm×2.1 mm,3.5μm)为分析柱,流动相为V(甲醇)∶V(纯水)=88∶12,流速为200μL/min;质谱条件选用气动辅助电喷雾离子源(ESI),检测方式为负离子多离子反应检测(MRM);PCP、TeCP标准曲线线性范围均为0.1~100μg/L;回收率为90%~99%;相对标准偏差为3.5%~7.6%(n=5);方法检测低限为5μg/kg。方法适用于纺织品中PCP、TeCP的测定。     

超高效液相色谱-串联质谱法测定鸡肉与鸡蛋中6种他汀类药物残留

建立了超高效液相色谱-串联质谱法(UPLC-MS/MS)测定鸡肉与鸡蛋中6种他汀类药物残留量的方法。采用BEH C18色谱柱,以甲醇-0.1%甲酸5 mmol乙酸铵为流动相,梯度洗脱分离,在电喷雾正负离子模式下以多反应监测(MRM)方式检测,外标法定量。6种他汀类药物检出限(LOD,S/N=3)和定量限(LOD,S/N=10)分别为0.1~0.5μg/kg和0.3~2.0μg/kg,在1.0~100μg/kg浓度范围内线性良好,相关系数大于0.9910;鸡肉和鸡蛋样品中20μg/kg水平的加标回收率分别为80.9%~97.2%和79.0%~87.2%,相对标准偏差分别为1.3%~10.2%和1.5%~10.7%。本方法应用于市场实际样品检测,尚未检出阳性样品。     

液相色谱串联质谱法对母婴纺织品中12种致敏性分散染料的同时测定

采用高效液相色谱-串联质谱仪(HPLC-MS/MS),在多反应监测(MRM)模式下建立了同时测定母婴纺织品中12种致敏性分散染料的快速分析方法。样品用甲醇超声提取,提取液过0.2μm滤膜后,经C18反相色谱柱分离,由串联质谱仪同时进行定性、定量分析。结果表明,12种致敏性分散染料在各自的线性范围内线性良好,r0.998;检出限(S/N=3)为0.2~2.0μg/kg;在5.0~100.0μg/kg范围内的低、中、高3个加标水平的平均回收率为73%~116%,相对标准偏差为1.3%~12.4%。方法操作简便、准确可靠,将其用于市场上母婴纺织品的测定,结果满意。     

微波辅助萃取/超高效液相色谱-静电场轨道阱高分辨质谱法同时测定纺织品中的抗菌剂和紫外光稳定剂

建立了超高效液相色谱-静电场轨道阱高分辨质谱(UPLC-Orbitrap HRMS)同时测定纺织品中7种抗菌剂和7种紫外光稳定剂含量的分析方法。以甲醇为萃取溶剂,85℃下微波萃取纺织品中的抗菌剂和紫外光稳定剂,萃取液经浓缩定容后进行UPLC/Orbitrap HRMS分析,外标法定量。以甲醇-0.1%甲酸水溶液(含5 mmol/L乙酸铵)为流动相,14种目标化合物在Hypersil GOLD色谱柱(100 mm×2.1 mm,1.9μm)上进行梯度洗脱。一级质谱扫描范围为m/z 100~500,14种目标化合物的质量数准确度误差均小于2×10-6(2ppm),其中对氯间二甲酚(PCMX)和三氯生采用电喷雾负离子模式,其余12种目标化合物均采用电喷雾正离子模式。通过目标化合物的保留时间和准分子离子峰的精确质量数进行定性,提取离子色谱图的峰面积进行定量。在各自的线性范围内,每种目标化合物的提取离子色谱图的峰面积均与其质量浓度线性相关,相关系数均大于0.998。在3个不同的加标浓度水平下,方法的平均加标回收率为80.1%~95.6%,相对标准偏差为2.9%~10.5%。方法的检出限(S/N=3)为0.1~0.3μg/kg。该方法定性可靠,定量准确,检出限低,完全可满足纺织品中抗菌剂和紫外光稳定剂含量检测的需要。     

气相色谱-负化学电离质谱法测定塑料中十七种邻苯二甲酸酯

建立了气相色谱-负化学电离质谱法(GC-NCI/MS)同时测定塑料中17种邻苯二甲酸酯(PAEs)的分析方法。塑料样品经二氯甲烷超声提取并过滤后进行检测。采用HP-5 MS毛细管色谱柱在程序升温条件下对滤液进行色谱分离,质谱采用负化学电离(NCI)模式,反应气采用氨气。17种PAEs在0.05~3.5 mg/L范围内线性关系良好,相关系数(r)均大于0.995;检出限为0.018~2.162 mg/kg;在100,500,1000,5000 mg/kg 4个添加水平下,17种PAEs的平均加标回收率为95.8%~106.5%,RSD(n=6)为2.6%~7.9%。方法可用于塑料产品中17种邻苯二甲酸酯的检测。     

直接竞争酶联免疫吸附法测定饲料中沙丁胺醇

应用本实验室制备的对沙丁胺醇(SAL)具有高亲和力的多克隆抗体和酶标半抗原,采用包被抗体-酶标半抗原直接竞争模式建立沙丁胺醇的酶联免疫吸附分析(ELISA)法。在优化实验条件下,ELISA法检测沙丁胺醇的线性浓度范围为0.1~1.0×10~3μg/L,沙丁胺醇对抗体-酶标半抗原结合反应的抑制中浓度(Ic50)为14μg/L,相对标准偏差(RSD)为8.6%(n=5),定量检测下限(Ic_(10))为0.29μg/L。在猪饲料中分别添加沙丁胺醇标样10、50、250μg/kg,ELISA法检测的回收率分别为85%~108%、81%~92%和81%~102%,RSD(n=5)分别为9.1%、5.6%和8.9%,对饲料中沙丁胺醇的最低定量检测浓度为4.23μg/kg。利用高效液相色谱-紫外检测(HPLC-UV)法同步测定饲料中添加250μg/kg沙丁胺醇的平均回收率为89%(n=3),相对标准偏差为3.9%。     

超高效液相色谱–串联质谱法测定饮用水中微囊藻毒素

建立饮用水中微囊藻毒素(MC–RR,MC–LR)的超高效液相色谱–串联质谱检测方法。样品经PVDF针式过滤头过滤后直接进样,采用喷雾正离子源(ESI~+)和多重反应监测模式(MRM)测定。MC–RR的质量浓度在0.02~10.00μg/L范围内与色谱峰面积呈良好的线性,线性相关系数r~2=0.998 9,检出限为0.096μg/L,测定结果的相对标准偏差为6.6%~9.1%(n=7),加标回收率为99.0%~103.0%。MC–LR的质量浓度在0.1~20μg/L范围内与色谱峰面积呈良好的线性,线性相关系数r~2=0.999 2,检出限为0.188μg/L,测定结果的相对标准偏差为4.3%~10.0%(n=7),加标回收率为93.0%~114.0%。该方法灵敏度高、重现性好,可用于饮用水中微囊藻毒素的检测。     

QuEChERS-超高效液相色谱-串联质谱法快速测定鱼肉中22种磺胺类药物残留

结合QuEChERS前处理技术,提出了测定鱼肉中22种磺胺类残留的超高效液相色谱-串联质谱法。样品用含0.1%(体积分数,下同)甲酸的乙腈溶液提取后,经QuEChERS试剂盒净化。净化液在Agilent ZORBAX Eclipse Plus C18色谱柱上分离,以0.1%甲酸溶液-甲醇为流动相进行梯度洗脱。采用电喷雾正离子源及计划式多反应监测模式进行测定,以内标法定量。磺胺硝苯、磺胺、磺胺喹噁啉的线性范围为0.5~50μg·L-1,检出限(3S/N)为0.5μg·L-1;其他19种磺胺类兽药的线性范围为0.1~50μg·L-1,检出限(3S/N)为0.1μg·L-1。加标回收率在78.2%~118%之间,测定值的相对标准偏差(n=6)在3.4%~19%之间。方法用于鱼肉中多种磺胺类药物残留的快速测定,结果与标准方法测定结果一致。     

稳定同位素稀释液质串联法测定抗菌纺织品中3种含氯防霉抗菌

建立了抗菌纺织品中三氯生、三氯卡班以及五氯酚等3种含氯抗菌剂的同位素稀释-液相色谱串联质谱的分析方法。样品用甲醇超声提取,聚酰胺粉净化。以水/乙腈为流动相,采用梯度洗脱,在Waters Acquity UPLC BEH C18色谱柱(2.1 mm×100 mm,1.7μm)上进行分离,以多反应监测负离子模式进行检测,内标法定量。三氯生和五氯酚在0.5~100.0μg/L,三氯卡班在0.1~50.0μg/L范围内具有良好的线性,样品的回收率为80.0%~110.0%,相对标准偏差(RSD)为1.6%~5.4%,方法的定量限为0.1~0.5μg/kg,检出限为0.03~0.16μg/kg。方法前处理简单,试剂可用于纺织品中三氯生、三氯卡班和五氯酚的含量检测。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.