高效液相色谱–串联质谱法同时测定塑料食品接触材料中20种邻苯二甲酸酯迁移量

采用高效液相色谱–串联质谱(LC–MS/MS)技术建立了食品接触材料中20种邻苯二甲酸酯类迁移量的测定方法。样品分别采用欧盟(EU)No.10/2011法规中食品模拟液浸泡,橄榄油浸泡液用乙腈进行液–液萃取,水基浸泡液直接过滤,C18色谱柱(100 mm×2.1 mm,2.7μm)分离,以0.1%甲酸溶液–甲醇溶液为流动相,梯度洗脱,采用多反应监控(MRM)模式进行分析检测。20种邻苯二甲酸酯类化合物质量浓度在1~500 ng/m L范围内与色谱峰面积呈线性关系。水溶液、3%乙酸食品模拟浸泡液、10%乙醇食品模拟浸泡液、20%乙醇食品模拟浸泡液、50%乙醇食品模拟浸泡液、橄榄油食品模拟浸泡液中方法定量限分别为0.20~9.81 ng/m L,0.19~9.76 ng/m L,0.25~12.3ng/m L,0.21~10.8 ng/m L,0.19~11.7 ng/m L,0.45~20.3 ng/m L。样品加标回收率为85.8%~111.3%(3%乙酸浸泡液),79.4%~123.6%(橄榄油浸泡液),两种浸泡液中测定结果的相对标准偏差不大于8.48%(n=6)。该方法具有快速简便、灵敏度高及准确性好等特点,适用于塑料类食品接触材料中邻苯二甲酸酯类迁移量的检测。     

混合型固相萃取/超高压液相色谱法测定废水中苯胺类化合物

通过对色谱分析、固相萃取和氮吹浓缩条件的优化研究,建立了混合型固相萃取/超高压液相色谱法测定废水中7种苯胺类化合物的方法。200 mL水样以5 mL/min通过MCX混合型固相萃取小柱,经4 mL2%甲酸水溶液锁定,4 mL 25%甲醇水溶液净化,8 mL 2%氨水甲醇溶液洗脱后,洗脱液经50℃氮吹浓缩至1 mL,微孔滤膜(0.22μm,尼龙)过滤后,采用BEH C18色谱柱(2.1 mm×50 mm,1.7μm)进行分离,以甲醇-乙酸铵溶液梯度洗脱,250 nm检测。7种苯胺类化合物可在6.5 min内实现基线分离,在0.1~5.0 mg/L范围内线性关系良好,相关系数均大于0.999,方法检出限(S/N=3)为0.10~0.50μg/L,定量下限(S/N=10)为0.33~1.67μg/L。在0.2μg和1.0μg加标水平下,回收率分别为52%~101%和54%~96%,RSDs分别为2.2%~11.3%和2.5%~9.0%。方法抗干扰能力强、分析速度快、灵敏度高,适用于废水中苯胺类化合物的测定。     

HPLC法快速测定熟肉制品中10种食品添加剂

建立了熟肉制品中10种食品添加剂的高效液相色谱分析方法。以乙醇–氨水溶液为提取溶剂,样品经超声波辅助溶剂萃取法萃取后,以Atlantis d C18(250 mm×4.6 mm,5μm)色谱柱为分离柱,20 mmol/L乙酸铵–甲醇为流动相进行分离测定。10种目标化合物的质量浓度在1.0~200.0 mg/L范围内与其峰面积线性关系良好(r0.999),在20.0,500.0,1 000.0 mg/kg的添加水平下,10种目标化合物的平均加标回收率为82%~104%,测定结果的相对标准偏差小于4.0%(n=6),方法的检出限为1.0~5.0 mg/kg(S/N=3)。该方法简单、快速、准确,适合于熟肉制品中食品添加剂的检测。     

液-液萃取/气相色谱-串联质谱测定纸制食品接触材料中9种挥发性全氟化合物前体物的迁移量

采用气相色谱-串联质谱(GC-MS/MS)技术建立了纸制食品接触材料中全氟脂肪醇、全氟丙烯酸酯和全氟磺酰胺等9种挥发性全氟化合物前体物的测定方法。样品采用欧盟(EU) 2017/752中食品模拟物3%乙酸、10%乙醇、50%乙醇和橄榄油浸泡,水基模拟物用二氯甲烷萃取,橄榄油浸泡液用乙腈萃取,DB-5MS(30 m×0. 25 mm×0. 25μm)色谱柱分离后,采用多反应监测(MRM)模式进行检测。9种化合物在5~500μg/L质量浓度范围内与峰面积呈线性关系。在3%乙酸、10%乙醇、50%乙醇及橄榄油食品模拟物中的方法定量下限分别为3. 3~4. 4、3. 5~4. 2、3. 3~4. 9μg/L和4. 2~5. 1 ng/g。样品加标回收率为85. 0%~115%,相对标准偏差(RSD,n=6)≤7. 8%。该法快速可靠、准确简便,适用于纸制食品接触材料中全氟化合物前体物的分析检测。     

超高效合相色谱法测定尼龙6食品接触材料中己内酰胺迁移量

建立了超高效合相色谱法测定尼龙6食品接触材料中己内酰胺迁移量的方法。样品经水、4%乙酸(V/V)、50%乙醇(V/V)、正己烷等4种食品模拟物浸泡后,50%乙醇、正己烷浸泡液直接进样,水、4%乙酸经乙醇稀释后进样,采用超临界CO2-甲醇(含2%水)为流动相进行梯度洗脱,经C18色谱柱(3.0 mm×100 mm,1.8μm)分离,通过PDA检测器对目标化合物在210 nm波长下进行分析,外标法定量。在优化条件下,己内酰胺在水、4%乙酸、50%乙醇、正己烷4种食品模拟物中,质量浓度范围分别在5.0~50.0 mg/L,5.0~50.0 mg/L,2.0~50.0 mg/L,5.0~50.0 mg/L线性良好,方法检出限分别为2.0,2.0,1.0,2.0 mg/L。进行添加回收实验,己内酰胺回收率为91.4%~98.4%,相对标准偏差为1.9%~3.2%。方法可用于食品接触材料中己内酰胺迁移量的快速测定。     

液相色谱-串联质谱法测定食品接触材料及制品中新戊二醇迁移量

采用液相色谱－串联质谱（LC－MS/MS）建立了食品接触材料及制品中新戊二醇的测定方法。样品采 用水、4%（体积分数,下同）乙酸、10%乙醇、20%乙醇、50%乙醇、95%乙醇和橄榄油作为食品模拟物进行 迁移试验后,水、4%乙酸、10%乙醇浸泡液直接过滤进样,其他乙醇类模拟物浸泡液采用氮吹方式去除大部 分乙醇后重新用水定容,橄榄油浸泡液采用 10% 乙醇萃取。经处理后的试液采用 ACQUITY UPLC? BEH C18 （50 mm × 2. 1 mm,1. 7 μm）色谱柱,以0. 01%甲酸溶液－乙腈为流动相进行梯度洗脱,在电喷雾离子源正离 子（ESI+ ）多反应监测（MRM）模式下进行检测,外标法定量。在优化条件下,新戊二醇在10～100 μg/L（μg/kg） 范围内线性关系良好,相关系数大于 0. 999。在 10、20、100 μg/L（μg/kg）3 个加标水平下,方法回收率为 92. 8%～117%,相对标准偏差（RSD）为0. 90%～8. 6%,检出限（LOD,S/N ≥ 3）为5 μg/L（μg/kg）,定量下限（LOQ, S/N ≥ 10）为10 μg/L（μg/kg）。该方法具有前处理简单易行、灵敏度高、稳定可靠的优点,涉及的食品模拟物 基本包括相关法规和标准中规定的类型,方法LOD和LOQ均低于相关法规和标准中的限量要求,能够满足食 品接触材料及制品中新戊二醇迁移量的检测需求,为相关产品监管和质量控制提供了可靠的技术手段。     

QuEChERS-高效液相色谱-串联质谱法测定动物源食品中阿奇霉素残留

建立了QuEChERS前处理,液相色谱-串联质谱测定动物源食品中阿奇霉素残留的快速分析方法。样品以乙腈提取,N-丙基乙二胺(PSA)净化,采用Zorbax Eclipse Plus C18柱(3.0 mm×100 mm,1.8μm)分离,以乙腈-0.1%甲酸溶液为流动相,梯度洗脱。阿奇霉素采用电喷雾正离子源(ESI+)、多重反应监测(MRM)模式检测,以保留时间和特征离子对(母离子和2个碎片离子)信息比较进行定性分析和定量分析。阿奇霉素在1.0~50.0 ng/m L范围内线性相关系数均大于0.995;在6种基质(鸡肉、牛肉、猪肉、猪肝、鲤鱼、牛奶)中方法的检出限(S/N=3)均为0.3μg/kg,定量限(S/N=10)均为1.0μg/kg;3个加标水平(1,2,10μg/kg)下,回收率为81.4%~103.8%,相对标准偏差为3.6%~8.9%。     

非抑制离子色谱法测定塑料食品接触材料中五种醇胺迁移量

建立了非抑制离子色谱法同时测定塑料食品接触材料中一乙醇胺(MEA)、二乙醇胺(DEA)、三乙醇胺(TEA)、三异丙醇胺(TIPA)、N,N-二乙基乙醇胺(DEAE)等5种醇胺类物质迁移量的方法。方法选用水、3%(m/V)乙酸、4%(V/V)乙酸、10%(V/V)乙醇、20%(V/V)乙醇、50%(V/V)乙醇、橄榄油、正己烷等8种物质作为食品模拟物,满足水性、酸性、醇类与脂类食品的模拟。在优化条件下,目标物检出限在0.03~2 mg/kg之间(S/N=3),加标回收率在84.1%~118.6%,精密度在0.92%~4.1%(n=6)之间。     

高效液相色谱-串联质谱法同时检测食品接触材料中9种抗氧剂的特定总迁移量

建立了高效液相色谱-串联质谱(HPLC-MS/MS)联用方法同时测定塑料制品食品模拟物(10%乙醇、20%乙醇、50%乙醇、3%乙酸和橄榄油)浸泡液中9种抗氧剂的特定总迁移量[SML(T)]。食品模拟物浸泡待测样品,冷却至室温并混匀,水基食品模拟物(10%乙醇、3%乙酸、20%乙醇、50%乙醇)用含0.05%三(2-羧乙基)膦盐酸盐(TCEP)60%的四氢呋喃水基食品模拟物溶液稀释5倍后,经亲水性聚四氟乙烯针头过滤器过滤后进样;橄榄油用甲醇正庚烷提取后,下清液用亲水性聚四氟乙烯针头过滤器过滤后进样。用C8柱梯度洗脱分离;质谱具电喷雾离子源,在负离子多反应监测(MRM)模式下运行;方法在5种食品模拟物中的定量限为0.01~0.3 mg/kg;水基食品模拟物在0.03~0.72 mg/L,0.06~1.44 mg/L,0.1~2.4 mg/L或0.3~7.2 mg/L,橄榄油食品模拟物在0.15~3.6 mg/kg,0.3~7.2 mg/kg,0.5~12.0 mg/kg或1.5~36 mg/kg范围内线性关系良好(R≥0.99240);0.3~21 mg/kg水平的加标回收率为74.4%~132%,相对标准偏差为0.8%~20%。方法满足欧盟(EU)NO 10/2011法规附表2中9种抗氧剂SML(T)的限量要求,并已应用于实际样品的检测。     

HPLC法快速筛查抗风湿类中成药或保健食品中21种非法添加化学成分

基于亚3μm核壳填料色谱柱技术建立了高效液相色谱法快速筛查21种抗风湿类化合物。供试品以1%乙酸-甲醇为提取溶剂,经ACCHROM C18100A(4.6 mm×100 mm,2.8μm)分离,以磷酸水溶液(pH3.0)-甲醇-乙腈溶液为流动相,梯度洗脱,检测波长为230 nm,流速1.0 m L/min,柱温35℃。该方法在20 min内可分离21种成分,各化合物的线性范围为5~100μg/m L(萘普生为1.5~30μg/m L),回收率为91.0%~109.1%。萘普生的检出限(S/N=3)为0.8 mg/kg,其余化合物的检出限为2.0 mg/kg。按上述方法对抽检样品进行检测,发现18批阳性样品,并采用液相色谱-质谱联用法进一步确证。该方法快速、准确,适用于抗风湿类中成药或保健食品中非法添加化学成分的快速筛查,具有广阔的应用前景。     

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。     

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。     

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.     

Calculation of enthalpies of hydrogenation of hydrocarbons

Sets of hydrogen molecule equivalents have been developed which permit the calculation of hydrogenation of different types of carbon-carbon bonds from ab initio total energies (3-21G and 6-31G* basis sets, and, to a more limited extent, for MP2/6-31G* data) of reactants and products. The calculated enthalpies of hydrogenation are in good agreement with experiment for unstrained molecules, with average errors on the order of 2 kcal/mol. The 6-31G* equivalents allow the enthalpies for strained molecules to be calculated accurately, but the 3-21G equivalents do not. The equivalents for both basis sets have been tested by calculating the enthalpies of hydrogenation of carbon-carbon bonds in nitrogen- and oxygen-containing organic molecules, free radicals, and classical carbocations. The results are in good agreement with experiment in most cases.     

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。