固相萃取-液相色谱-串联质谱法测定猪栏废水中10种抗生素

应用固相萃取-液相色谱-串联质谱法测定养猪废水中10种抗生素的含量。水样由盐酸调节pH至2.5~4.0,流经Oasis HLB固相萃取柱富集后再用甲醇洗脱。以Aglient eclipse XDB C18色谱柱为分离柱,以不同体积比的0.1%(体积分数)甲酸溶液和乙腈混合液为流动相进行梯度洗脱,采用电喷雾正离子源多反应监测模式检测。10种抗生素在一定的质量浓度范围内与其峰面积呈线性关系,方法的检出限(3S/N)在0.03~3.5μg·L-1之间。加标回收率在53.2%~104%之间,测定值的相对标准偏差(n=6)在0.5%~6.3%之间。     

高效液相色谱-串联质谱法同时测定配合饲料中维生素B_1和维生素B_2

采用高效液相色谱-串联质谱法同时测定配合饲料中维生素B1和维生素B2。样品经20mmol·L-1甲酸铵溶液提取后,采用Tigerkin C8色谱柱分离,以甲醇-20mmol·L-1甲酸溶液为流动相进行梯度洗脱,采用电喷雾正离子源-选择多反应监测模式检测,外标法定量。维生素B1和维生素B2的质量分数在20.0~500μg·kg-1范围内与其峰面积呈线性关系,检出限(3S/N)均为50μg·kg-1。对虾饲料进行加标回收试验,回收率在88.0%~120%之间,测定值的相对标准偏差(n=6)为0.90%~2.7%。方法已应用于市售配合饲料中维生素B1和维生素B2的测定。     

固相萃取-高效液相色谱-原子荧光光谱法联用测定水中无机汞(Ⅱ)及有机汞

采用固相萃取-高效液相色谱-原子荧光光谱法联用技术测定了水样中无机汞及有机汞。水样流经以DDTC溶液改性的C18固相萃取小柱。用含有10%(体积分数)乙腈的混合洗脱液4mL,分4次,以1~2mL·min-1流量从小柱上将3种形态的汞洗脱。收集洗脱液,混匀,过滤后通过Venusil MP C18色谱柱,用乙腈、145mmol·L-1乙酸铵溶液和20mmol·L-1半胱氨酸溶液(5+45+50)混合液作为流动相进行色谱分离。根据选定的形态分析条件,用原子荧光光谱法进行测定。汞质量浓度在0.5~20μg·L-1范围内与其峰面积呈线性关系,汞(Ⅱ)、甲基汞、乙基汞的检出限(3S/N)依次为1.6,0.5,1.2ng·L-1。加标回收率在71.2%~95.2%之间,测定值的相对标准偏差(n=6)在4.9%~10%之间。     

超高效液相色谱-串联质谱法测定减肥类保健品中的西布曲明

采用超高效液相色谱-串联质谱法测定减肥类保健品中的西布曲明。样品经甲醇超声提取后,使用Phenomenex Kinetex C18色谱柱分离,以乙腈-10mmol·L-1乙酸铵溶液(含0.1%甲酸)为流动相进行梯度洗脱,质谱中选择多反应选择离子监测模式检测,以西布曲明-D6作为同位素内标进行定量。西布曲明的质量浓度在5.00~400μg·L-1范围内呈线性,测定下限(10S/N)为10ng·g-1。加标回收率在97.0%~104%之间,相对标准偏差(n=9)为1.1%~3.0%。     

高效凝胶色谱法测定角膜接触镜护理液中羟丙甲纤维素含量

采用高效凝胶色谱法测定角膜接触镜护理液中有效成分羟丙甲纤维素的含量,探讨护理液中其他润滑成份对测定的影响和评价。选择市场上含有羟丙甲纤维素的角膜接触镜护理液,以水凝胶色谱柱(TSK-Gelα3000与TSK-Gelα3000串联)为分离柱,以50mmol·L-1氯化钠溶液为流动相,流量为0.7mL·min-1,示差折光检测器测定。羟丙甲纤维素的质量浓度在0.1~5.0g·L-1范围内与其峰面积呈线性关系,检出限(3S/N)为0.056g·L-1。应用本方法对角膜接触护理液进行加标回收试验,回收率在98.0%~102%之间。对羟丙甲纤维素标准溶液平行测定6次,测定值的相对标准偏差(n=6)小于1.5%。     

高效液相色谱-串联质谱法测定食品中维生素D_2和维生素D_3

提出了食品中维生素D2和维生素D3的高效液相色谱-串联质谱分析方法。食品样品经氢氧化钾皂化后乙醚萃取,所得有机相经无水硫酸钠除水后蒸发至干。用1 mL乙醇溶解后经Agilent Zorbax XDB C18色谱柱(2.1 mm×50 mm,3.5μm)分离,用甲-醇10 mmol·L-1乙酸铵溶液(90+10)的混合溶液洗脱,采用电喷雾正离子模式多反应监测。维生素D2和维生素D3的线性范围均为50~500μg·L-1,检出限(3S/N)均为10μg·L-1。方法应用于测定奶粉和酸酸乳中维生素D2和维生素D3,回收率在76.8%~83.9%之间。     

高效液相色谱-串联质谱法测定猪肉中9种β_2-受体激动剂残留量

采用高效液相色谱-串联质谱法测定了猪肉中9种β-受体激动剂的残留量。样品经β-葡萄糖醛苷酶/芳基硫酸酯酶酶解后加入高氯酸沉淀蛋白并离心,取上清液过PCX阳离子固相萃取小柱净化,用氨水-甲醇(5+95)混合液洗脱,氮气吹干后用乙腈定容至1 mL。以CAPCELL PAK CR色谱柱为分离柱,以10mmol·L-1乙酸铵溶液-乙腈(55+45)混合溶液(含体积分数为0.1%的甲酸)为流动相进行洗脱,采用电喷雾正离子源及选择反应监测模式进行测定,内标法进行定量。9种β-受体激动剂的质量浓度在4.00~100μg·L-1范围内与其峰面积呈线性关系,方法的检出限(3S/N)在0.09~0.50μg·L-1之间。对空白样品进行加标回收试验,回收率在83.2%~102%之间,测定值的相对标准偏差(n=6)在5.0%~12%之间。     

高效液相色谱-串联质谱法测定农产品中矮壮素残留量

提出了农产品中矮壮素的高效液相色谱-串联质谱(HPLC-MS/MS)分析方法。样品经甲醇-水(1+1)溶液提取,正己烷液液萃取后,采用阳离子交换固相萃取柱净化。所得净化液以阳离子交换树脂与C18混合填料色谱柱为固定相,以含0.1%(体积分数)乙酸的乙腈-10mmol·L-1乙酸铵(1+1)溶液为流动相进行等度洗脱,采用电喷雾正离子源,多反应监测模式检测,同位素内标法定量。矮壮素的线性范围为1.0~100μg·L-1,检出限(3S/N)为5μg·kg-1,测定下限(10S/N)为10μg·kg-1。矮壮素在10,100,500μg·kg-1等3个加标水平的回收率为90.5%~98.5%之间,测定值的相对标准偏差(n=6)在0.99%~2.2%之间。     

液相色谱-串联质谱法测定葡萄酒中赭曲霉毒素A、B的残留量

采用液相色谱-串联质谱法测定葡萄酒中赭曲霉毒素A、B的残留量。样品用氨水调节pH后离心,上清液过C18固相萃取柱净化,以甲醇洗脱,氮气吹至近干后用甲醇-0.15%甲酸(7+3)溶液定容至1mL。以Agilent Eclipse XDB-C18色谱柱为分离柱,以甲醇-含5mmol·L-1乙酸铵溶液的0.15%甲酸溶液(7+3)混合液为流动相进行洗脱,采用电喷雾离子源及选择多反应监测模式进行测定。赭曲霉毒素A、B的线性范围在10.0μg·L-1以内,方法的测定下限(10S/N)均为2.0μg·L-1。对空白样品进行加标回收试验,回收率在66.3%~87.4%之间,测定值的相对标准偏差(n=6)在5.2%~7.6%之间。方法用于葡萄酒中赭曲霉毒素A、B的测定,结果与美国化学家协会检测方法的测定结果一致。     

免疫亲和层析净化-高效液相色谱法测定大米中桔霉素

大米样品经甲-醇10 mmol.L-1磷酸溶液(70+30)提取,提取液稀释过滤后经CitriTestTM免疫亲和柱层析净化后用高效液相色谱法测定其桔霉素的含量。以Kromasil 100-10 C18色谱柱(250 mm×4.6 mm,5μm)为分离柱,甲酸(1+99)溶液与乙腈以体积比1比1混合的溶液作流动相,采用荧光检测,激发波长为350 nm,发射波长为500 nm。必要时采用液相色谱-串联质谱法对结果作验证。桔霉素的质量浓度在5.0~500.0μg.L-1范围内与其峰面积呈线性关系,测定下限(10S/N)为10.0μg.kg-1。方法的回收率为73%~76%,相对标准偏差(n=8)为7.5%~11.8%。     

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.     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

Synthesis of phenolic components of Grains of Paradise

Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.     

Acid hydrolysis of carboxymethylcellulose of low degree of substitution

Cotton cellulose was swollen in a sodium hydroxide solution and carboxymethylated by a two-bath method for different periods of time for each process. The kinetics of acid hydrolysis and the crystallinity of the swollen and carboxymethylated samples were measured. The proportion of broken bonds, rate constants for hydrolysis, and permeability of cellulose to hydrolyzing agents were calculated. The susceptibility of glycosidic linkages to acid hydrolysis was improved by carboxymethylation more than by swelling in alkali. The increased accessibility of carboxymethylcellulose to acid was regarded as a consequence of increased intra-and intercrystalline swelling and of the glycosidic bonds' weakness caused by the electron-attracting carboxymethyl group on the C-6 position.     

Study of hydration of two cements of different strengths

Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, M_o, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700^oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.     

恶臭嗅辨实验室建设探讨

针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。     

Estimation of Kinetic Parameters of Thermal Oxidation of Ilmenite

The aim of the presented work was the investigation of thermal oxidation of ilmenite in static air atmosphere. The investigations were carried out by use of a derivatograph (MOM, Hungary). The changes of crystallographic structure of investigated samples were identified by X-ray diffractometry on Philips PW-1710 diffractometer. In temperature above 500°C appears structure of hematite Fe₂O₃. On the basis of the thermogravimetric measurements, the contracting area and contracting volume models were found as the best fitting experimental data. This revised version was published online in August 2006 with corrections to the Cover Date.     

Mechanism of action of base-catalyzed oxygenation of phenol derivatives

Cyclopropyl derivative of 2,6-di-tert-butylphenol is synthesized as a probe to investigate the mechanism of base-catalyzed autooxidation of phenol derivatives. Our study indicates that one electron reduction of molecular oxygen from phenolate gives phenoxyl radical 3, a key intermediate of autooxidation. The coupling of phenoxyl radical and superoxide radical gives peroxylate anion 4 and produces the final epoxy alcohol adduct 6.     

氯氧化镁生成热的研究

用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。