高效液相色谱-串联质谱法检测中药材中有机磷农药残留量

研究了中药材中有机磷农药残留量的高效液相色谱-串联质谱同步检测方法.采用CAPCELL PAK MC C18反相柱,以乙腈为提取溶液,以Carb/PSA柱为净化柱,液相色谱-串联质谱仪测定.方法线性范围为10～500 μg/L,11种有机磷农药在此范围内线性良好,相关系数为0.9961～0.9999.在10～100 μg/kg浓度范围内,加标回收率在70%～110%之间,相对标准偏差为1.4%～11%,最低检出限为2～20μg/kg,符合残留检测分析要求.     

高效液相色谱-串联质谱法同时测定蜂胶、蜂胶原料保健食品中的氯霉素、甲砜霉素与氟甲砜霉素

建立了同时测定蜂胶、蜂胶原料保健食品(片剂、硬胶囊、软胶囊3种剂型)中氯霉素、甲砜霉素和氟甲砜霉素残留的高效液相色谱-串联质谱(HPLC-MS/MS)方法。样品经0.1 mol/L盐酸溶解,涡旋混匀,超声提取后,通过HLB柱串接NH_2固相萃取柱净化。采用Waters ACQUITY UPLC~?BEH C_(18)(2.1 mm×100 mm,1.7μm)色谱柱进行分离,以0.1%甲酸水-乙腈为流动相梯度洗脱,经HPLC-MS/MS测定,电喷雾离子源负离子模式检测,外标法定量。结果表明3种目标分析物在0.10～20.0μg/L范围内线性关系良好,相关系数(r~2)均大于0.999;蜂胶原胶、片剂和软胶囊剂型中3种目标物的检出限(LOD)为0.037～0.083μg/kg,定量下限(LOQ)为0.12～0.28μg/kg;硬胶囊剂型中的LOD为0.39～0.47μg/kg,LOQ为1.28～1.57μg/kg;在2.5、5.0、10.0μg/kg加标水平下,3种目标物的回收率为66.6%～120%,相对标准偏差(RSD)为0.80%～11%。将该方法应用于45个实际样品检测,其中氯霉素的检出率为22.22%,最大残留量为14.32μg/kg;氟甲砜霉素的检出率为17.78%,最大残留量为21.62μg/kg。该方法操作简单、灵敏度高、适用性强,能够满足蜂胶、蜂胶原料保健食品中此类药物残留的检测要求。     

超高效液相色谱-串联质谱法测定鸡肉中头孢拉定残留

建立测定鸡肉中头孢拉定残留的超高效液相色谱-串联质谱分析方法。鸡肉样品经80%乙腈水溶液提取,PRiME HLB柱固相萃取净化,0.2%甲酸水溶液稀释,采用Waters ACQUITY UPLC HSS T3色谱柱(100 mm×2.1 mm,1.8μm)分离,以0.1%甲酸-0.1%甲酸乙腈为流动相,梯度洗脱,基质加标外标法定量。实验结果表明,头孢拉定在0.5～50.0 ng/mL浓度范围内呈良好的线性关系(R~2=0.9998),定量限为1μg/kg。向空白鸡肉中添加头孢拉定含量为1.00μg/kg、2.00μg/kg、10.0μg/kg时,回收率在77.3%～106.8%之间,相对标准偏差在3.2%～10.5%之间。本方法操作简便、快捷,实验结果准确、稳定,可满足鸡肉中头孢拉定残留量的检测。     

在线净化液相色谱串联质谱法测定动物源食品中金刚烷胺的残留

建立了在线净化液相色谱串联质谱法测定动物源食品中金刚烷胺的残留。样品用甲醇-1%三氯乙酸或乙腈提取,提取液用阳离子交换在线净化柱(Cyclone MCX)净化,5%氨水-甲醇溶液将分析物洗脱转入至Capcell Pak MG C18分析柱,经色谱分离后,用串联质谱检测。方法的定量限(LOQ)牛奶为0.25μg/kg,动物组织和鸡蛋为0.5μg/kg,在0.1～20μg/L浓度范围内呈良好线性,线性相关系数大于0.9995。方法在3个水平的添加回收率为83.3%～93.6%,相对标准偏差在3.5%～5.9%之间。方法简单快速,回收率高,重现性好,适用于动物源食品中金刚烷胺残留的定量及确证分析。     

超高效液相色谱-串联质谱法同时测定畜禽肉中磺胺类、喹诺酮类、硝基咪唑类兽药残留

建立了固相萃取-超高效液相色谱-串联质谱法同时测定畜禽肉中7种磺胺类、3种喹诺酮类及4种硝基咪唑类残留的方法。样品经乙腈提取,正己烷脱脂,MCX小柱净化后,由超高效液相色谱分离、三重四极杆质谱检测,基质外标法定量。14种兽药含量在1~50.0μg/L范围内线性关系良好,相关系数均大于0.994,加标回收率为75.2%~103.4%,检出限为0.1~0.5μg/kg,空白加标重复测定的相对标准偏差(n=6)为2.3%~12%。方法适用于畜禽肉中多种兽药残留的快速测定。     

固相萃取净化-气相色谱/串联质谱法测定茶叶中54种农药残留量

建立了固相萃取净化-气相色谱/串联质谱(SPE-GC-MS/MS)分析茶叶中54种农药残留的方法。样品用乙睛提取,提取液经石墨化炭黑/氨基固相萃取柱净化后,采用气相色谱-串联质谱方法在分时段选择反应监测模式下进行测定,外标法定量。当54种农药加标水平为10、50、100μg/kg时,回收率为60%～150%,方法的相对标准偏差小于16%;定量限(LOQ)均小于10μg/kg;在20～320μg/L范围内线性关系良好。方法已用于同时检测茶叶中农药多残留。     

高效液相色谱-串联质谱法测定猪肉中泰拉霉素残留

建立了高效液相色谱-串联质谱(HPLC-MS/MS)测定猪肉样品中新型兽药泰拉霉素残留的方法.样品用V(甲醇): V(0.1% H3PO4)=70: 30混合溶液提取,经离心后用PCX固相萃取小柱净化, 以SymmetryC8色谱柱为分离柱,在串联质谱多反应监测(MRM)模式下检测,内标法定量.方法的线性范围为10～500 μg/kg,检出限为5.0 μg/kg,在3个浓度水平(10,20和50 μg/kg)进行添加实验,平均回收率为93.1%～105.5%; 批内相对标准偏差为1.5%～4.6%; 批间相对标准偏差为1.8 %～5.6%.     

TurboFlow在线净化/液相色谱-串联质谱法快速测定动物源性食品中聚醚类抗生素的研究

建立了Turbo Flow在线净化/液相色谱-串联质谱法快速同时测定牛奶、鸡肉和鸡蛋中拉沙洛菌素、盐霉素、莫能菌素、甲基盐霉素、马杜霉素和尼日利亚菌素残留的方法。样品提取液经在线净化柱Cyclone-p净化,Thermo Scientific Hypersil-Gold C8(150 mm×2.1 mm,5μm)色谱柱分离,电喷雾正离子模式测定,整个分析过程仅13 min。方法在1~100μg/L范围内呈良好线性关系(r≥0.999),定量下限为1μg/kg,在动物源性食品中3个加标水平下的回收率为71.9%~109.0%,相对标准偏差为1.5%~14.9%。     

同位素内标-高效液相色谱串联质谱法测定乳及乳制品中13种β-受体激动剂类药物残留

建立了乳及乳制品中13种β-受体激动剂类药物多残留的同位素内标-高效液相色谱串联质谱分析方法。样品经三氯乙酸沉淀蛋白,提取液经SupelcleanLC-SCX固相萃取柱净化后,用HPLC-MS/MS进行测定。采用AgilentEclipse Plus C18色谱柱(2.1×150 mm,3.5μm),0.1%甲酸水-乙腈流动相进行梯度洗脱,用电喷雾离子源正离子多反应监测(MRM)模式进行MS/MS检测。其中克伦特罗在0.05～5.0μg/kg线性范围内,其余12种分析物在0.25～10μg/kg线性范围内具有较好的线性关系,相关系数r>0.9988。方法检出限(LOD)为0.02～0.17μg/kg,定量限(LOQ)为0.05～0.48μg/kg。空白样品添加回收率为83.2%～102.6%,相对标准偏差为5.0%～13%。     

超高效液相色谱-串联四极杆质谱法测定水产品中氯霉素残留量

建立超高效液相色谱-串联四极杆质谱法测定水产品中氯霉素残留量的方法。样品均质后经乙酸乙酯提取,正己烷脱脂(或用固相萃取柱净化),超高效液相色谱分离,串联四级杆质谱检测,同位素内标法定量。方法在0.05～1.0μg/kg的添加范围内的平均回收率为84.9%～103.3%,相对标准偏差为3.2%～5.2%,定量检测限为0.02μg/kg。方法适用于各种水产品基质的氯霉素残留检测。     

利用手持技术改进测定乙醇分子结构实验

利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。     

Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.     

光谱仪测试范围的扩展

由于石化行业的生产需要，其材质的使用具有多样性和广泛性，经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识，根据光谱仪的测试能力及标样的采集，实现了一个或几个元素测量范围的扩展，并对其测量的影响因素进行了研究。     

Influence of viscosity of medium on processes of oxygen quenching of excited states of mesoporphyrin

The oxygen quenching rate constants for singlet and triplet excited states of the dimethyl ester of mesoporphyrin IX increase with decreasing viscosity of the medium and reach a maximum at a viscosity of approximately 0.4 mPa·sec, after which the rate constants begin to decrease. The drop in rate constant with increasing fluidity of the medium may be related to a nonequilibrium character of the elementary act in the interaction of the reactants in the solvent cage. In viscous media such as isopropyl alcohol, isobutyl alcohol, and isoamyl alcohol, the reaction radius is greater than the sum of the radii of the reacting particles. The long-range character of these processes is due to the relatively weak dependence of the quenching probability on distance.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 161–167, March–April, 1989.     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

物质分配系数的测定实验改进

实验教学目的是从解决实际问题出发,以实验技术训练和实验设计思想培养为目标。介绍了将单一的物质分配系数测定实验改进为综合实验,提高了实验效果及实验资源利用率。     

Effect of the Method of Modification of Zeolite X on Selectivity of Catalytic Methylation of Toluene

Theoretical and Experimental Chemistry - The effect of the method of modification of catalysts based on zeolite X by cesium and magnesium cations (ion exchange and impregnation) on the selectivity...