超高效液相色谱-串联质谱法测定化妆品中61种性激素

建立了一种超高效液相色谱-串联质谱法测定化妆品中61种性激素的方法。水基类、乳液类、膏霜类和凝胶类化妆品经乙腈分散,50%(V/V)乙腈水溶液超声提取;油基类样品经正己烷分散,70%(V/V)乙腈水溶液涡旋提取。采用CORTECS C18(2.1 mm×150 mm, 2.7μm)色谱柱进行分离,选择乙腈、水为流动相进行梯度洗脱,多反应监测(MRM)模式检测,基质外标法定量。结果表明,61种性激素的检出限和定量限分别为0.03～0.31μg/g和0.09～0.92μg/g,在15～150μg/L范围内线性关系良好(相关系数R²>0.99)。选择了5种化妆品基质,在低、中、高3个加标水平下,61种性激素的加标回收率为80.0%～117.7%,相对标准偏差(RSD)为1.5%～14%。该方法可以为化妆品的快速风险筛查和国家标准的制修订提供技术支撑。     

固相萃取/超高效液相色谱-串联质谱法测定儿童化妆品中新康唑等4种抗生素

建立了测定儿童化妆品中新康唑等4种抗生素的超高效液相色谱-串联质谱法(UPLC-MS/MS)。样品经70%乙腈水溶液超声提取后,使用SCX固相萃取小柱净化,以0.1%甲酸水和乙腈作为流动相,经Waters ACQUITY BEH C₁₈(2.1 mm×100 mm,2.5μm)色谱柱分离,使用多反应监测模式(MRM)进行测定。结果表明,4种抗生素线性关系良好,相关系数(r)均为0.999,方法检出限(LOD)和定量下限(LOQ)分别为0.005～0.250μg/g和0.010～0.500μg/g。4种抗生素在3种基质和3个加标水平的平均回收率为89.3%～113%,相对标准偏差(RSD)为0.90%～7.2%。该方法高效、准确、特异性好,满足新康唑等4种抗生素在儿童化妆品中的测定需求。     

超高效液相色谱-串联质谱法同时测定化妆品中83种糖皮质激素

近年来化妆品中非法添加糖皮质激素的恶性事件常有发生，因此建立一个高通量且简便高效的检测方法，对保障消费者的用妆安全具有现实意义。研究建立了超高效液相色谱-串联质谱法同时测定化妆品中83种糖皮质激素的分析方法。以化妆品中常用的水、乳液、膏霜(o/w型)3种基质为研究对象，对样品前处理和色谱-质谱条件进行优化，最终确定样品经乙腈涡旋分散、超声提取、过滤后，采用Thermo Accucore PFP色谱柱(100 mm×2.1 mm, 2.6μm)分离，以0.1%(v/v)乙酸乙腈和0.1%(v/v)乙酸水溶液为流动相梯度洗脱，在电喷雾正离子模式(ESI⁺)下以动态多反应监测(MRM)方式测定，外标法定量。结果表明，83种糖皮质激素在2～200μg/L范围内线性关系良好，相关系数(r)均大于0.995,在3个不同添加水平下，平均回收率为74.5%～112.4%,相对标准偏差(RSD,n=6)为0.8%～9.9%,方法的检出限(LOD,S/N≥3)和定量限(LOQ,S/N≥10)分别为0.001～0.023μg/g和0.002～0.076μg/g。采用该方法对市售的41批...     

冷冻去脂-液液分配净化/气相色谱-质谱法测定化妆品中16种多环芳烃

建立了保湿护肤系列化妆品中16种多环芳烃的气相色谱-质谱测定法。对于水剂样品,采用环己烷提取、浓缩等简单前处理;对于膏霜剂样品,采用乙腈+丙酮(8+2,V/V)涡旋提取样品中的待测物,提取液经冷冻去脂、液液萃取净化(氨水-环己烷、水-环己烷),气相色谱-质谱法测定。16种多环芳烃在1～50μg/L均与对应峰面积呈良好线性关系。添加量在1～50μg/kg时,平均回收率(n=6)为78.1%～103.7%,相对标准偏差为2.4%～7.1%,方法检测限为1～10μg/kg。该法可用于化妆品中16种多环芳烃的测定。     

通过式高效净化/超高效液相色谱-串联质谱法测定化妆品中73种糖皮质激素

建立了超高效液相色谱-串联质谱(UPLC-MS/MS)同时测定化妆品中73种糖皮质激素的分析方法。样品采用饱和氯化钠分散,乙腈超声提取,经PRiME HLB固相萃取柱(60 mg/3 mL)净化,采用Waters Cortecs C_(18)色谱柱(150 mm×2.1 mm,2.7μm)分离,以0.1%乙酸溶液-乙腈为流动相梯度洗脱。在电喷雾离子源正离子模式下,采用多反应监测(MRM)扫描方式测定,外标法定量。结果表明,73种糖皮质激素在各自的质量浓度范围内均呈良好线性关系,相关系数(r)均大于0.99,定量下限(LOQ)为0.1～0.3μg/g。在1LOQ、2LOQ、5LOQ 3个加标水平下,73种糖皮质激素的回收率为73.3%～119%,相对标准偏差(RSD)为0.40%～18%。该方法快速、准确、高效,可作为化妆品中73种糖皮质激素的筛查方法。     

高效液相色谱-串联质谱法同时测定精油类化妆品中31种生物碱

建立了一种同时测定精油类化妆品中31种生物碱的高效液相色谱-串联质谱(HPLC-MS/MS)分析方法。样品以含有2%甲酸的甲醇-水(3∶1,体积比)为提取溶剂,正己烷除脂;采用HPH-C_(18)色谱柱(2.7μm,100 mm×2.1 mm)分离,以0.2%甲酸水溶液-乙腈为流动相梯度洗脱,流速为0.35 mL/min,在电喷雾正离子模式下以多反应监测(MRM)方式测定。结果表明:31种生物碱在相应的质量浓度范围内线性关系良好,相关系数(r)为0.992 8～1.000 0。方法检出限为0.09～3.03μg/kg,定量下限为0.31～10.12μg/kg,3个加标水平下的回收率为63.3%～126%,相对标准偏差为0.73%～17%。该方法前处理简便高效,测定结果准确,灵敏度高,适用于精油类化妆品中生物碱的检测及化妆品的安全性评价。     

超高效液相色谱-串联质谱法同时测定化妆品中13种性激素含量

建立了超高效液相色谱-串联质谱法(UPLC-MS/MS)同时测定化妆品中13种性激素含量的分析方法。液态水基类、液态油基类、膏霜乳液类(含面膜)化妆品采用50%乙腈超声提取,经C18色谱柱分离,采用动态多反应监测(DMRM)扫描方式测定。结果表明,13种性激素的检出限(LODs)为0.001~0.026μg/g,在0.89~64.80μg/L范围内线性关系良好,相关系数(r)均大于0.995。回收率为80.8%~116.8%,相对标准偏差(RSD,n=6)为0.7%~14.4%。该方法高效、灵敏、准确,填补了化妆品中醋酸氯地孕酮、己酸羟孕酮等化合物的测定方法空白,可作为化妆品中性激素类物质的通用检测方法,适用于多种基质化妆品中性激素的快速筛查。     

高效液相色谱法测定化妆品原料中N-乙酰神经氨酸

建立高效液相色谱法测定化妆品原料中N-乙酰神经氨酸含量的方法。以体积分数为50%的乙酸溶液为水解溶剂,样品于80℃水浴中加热30 min,以CAPCELL PAK SCX柱（250 mm×4.6 mm,5μm）为分析柱,流动相为乙腈-0.1%磷酸水溶液（体积比为80∶20）,等度洗脱,流量为1.0 mL/min,柱温为35℃,采用高效液相色谱二极管阵列检测器测定,以色谱峰面积外标法定量。检测波长为205 nm,进样体积为10μL。N-乙酰神经氨酸的色谱峰面积与质量浓度在10.0～500.0μg/ml范围内线性关系良好,相关系数为0.999 9,方法检出限为0.12μg/mL,定量限为0.4μg/mL。样品加标平均回收率为97.7%～98.9%,测定结果的相对标准偏差为0.37%～1.36%(n=6)。该方法样品处理简便、高效,适用于化妆品原料中N-乙酰神经氨酸的含量测定。     

超高效液相色谱-串联质谱法同时测定尿液与血清中23种双酚类化合物

建立了基于吡啶-3-磺酰氯衍生和超高效液相色谱-串联质谱(UPLC-MS/MS)检测尿液和血清中23种双酚类化合物(BPs)的方法。尿液样品采用乙酸乙酯提取;血清样品采用乙腈提取,上清液经PRiME HLB柱净化。提取液经吡啶-3-磺酰氯衍生后,以乙腈和0.1%甲酸水溶液为流动相,采用ACQUITY UPLC BEH C_(18)(2.1 mm×100 mm,1.7μm)色谱柱进行分离。质谱离子源为电喷雾电离源,正离子模式检测。23种目标物在0.005～100μg/L范围内线性关系良好,检出限为0.002～0.030μg/L,定量下限为0.005～0.100μg/L,回收率为76.6%～122%,相对标准偏差(RSD)为0.60%～14%。使用建立的方法分别对20份尿液和20份血清样品进行了检测。该方法样品用量少,灵敏度高,可以满足尿液和血清样品中23种BPs的同时测定要求。     

高效液相色谱法同时测定化妆品中9种4-羟基苯甲酸酯类防腐剂

建立同时测定化妆品中9种4-羟基苯甲酸酯类防腐剂的高效液相色谱法。样品经甲醇溶解,超声提取,使用Waters Symmtery C_(18)(2.1 mm×250 mm,5μm)色谱柱,用0.1%磷酸溶液–乙腈为流动相进行梯度洗脱,采用二极管阵列检测器进行检测,检测波长为254 nm,外标法定量。9种防腐剂的质量浓度在0.1~100μg/mL范围内与对应的色谱峰面积线性关系良好,相关系数为0.9993~0.9997,检出限为0.65~2.22μg/g,定量限为2.18~7.39μg/g。样品在25、50、250μg/g 3个加标水平时的平均回收率为95.73~104.06%,测定结果的相对标准偏差为0.58~5.28%(n=6)。该方法简单、准确、灵敏,可用于化妆品中9种4-羟基苯甲酸酯类防腐剂的测定。     

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.