Optimization of Gas Chromatography-electron Ionization-tandem Mass Spectrometry for Determining Toxic Non-ortho Polychlorinated Biphenyls in Breast Milk

One of the most commonly used non-invasive methods for assessing human exposure to pollution is the analysis of human milk.Human milk analyses help estimate the exposure of infants[1].This is why breast milk is receives scientific interest,and various methods for determining different pollutants from the environment are being developed[2,3].

Coupling a Gas Chromatography Unit to an Inductively Coupled Plasma Mass Spectrometer

Although the eminent threat of a terrorist group detonating an improvised nuclear device (IND) in an urban environment is low, it is crucial that countries develop modern nuclear forensic capabilities to expedite response in a post-detonation scenario. In particular, new instruments need to be created to shorten dissolution time, expedite chemical separation, and improve forensic analysis of the nuclear melt glass that is created during the detonation of the device. To expedite this process, an instrument was designed to thermally couple a gas chromatograph (GC) to a time-of-flight inductively coupled plasma time-of-flight mass spectrometer (ICPTOFMS) In order to couple these two instruments, another instrument was designed to provide an isothermal atmosphere between the GC and TOFICPMS to expedite rapid gas separations processes. By using gas separations instead of the current wet chemistry processes, the required separation and analysis time of the melt glass significantly decreases. The new instrument would also provide a more detailed analysis of the elemental and isotopic composition of the melt glass. By completing these tasks simultaneously, this significantly decreases the required time to conduct these separations and improves the elemental and isotopic analysis.

Sex Pheromone Components of the Female Black Cutworm Moth in China: Identification and Field Trials

The sex pheromone blend of a China strain of the black cutworm moth Agrotis ypsilon （Rottemberg） （Lepidoptera： Noctuidae） was investigated. Chemical analysis of pheromone gland extracts of 3-day-old females showed that individual isolated glands contained only very small amounts of pheromone. The high-resolution gas chromatography combined with mass spectrometry （GC-MS） analysis showed the presence of Cis-7-dodecenyl acetate （Z7-12：Ac, A）, Cis-9-tetradecenyl acetate （Z9-14：Ac, B）, Cis- 11-hexadecenyl acetate （Z 11 - 16 ：Ac, C）, Cis-8-dodecenyl acetate （Z8-12：Ac, E） and Cis-5-decenyl acetate （Z5-10：Ac, D） in biologically active pheromone gland extracts. An extract of one gland from a day 3 female gave the following values for the gland components： 0.245±0.098ng for Z7-12：Ac, 0.080±0.031ng for Z9-14：Ac, 0.089±0.033ng for Z11-16：Ac, 0.085±0.031ng for Z5-10：Ac, 0.105±0.065ng for Z8-12：Ac per female. The percentages of Z7-12：Ac, Z9-14：Ac, Z11-16：Ac, Z5-10：Ac and ZS-12：Ac in pheromone gland extracts from individual females were （meaniSE） 40.451±13.66, 13.176±5.279, 14.943±5.142, 14.392±6.10 and 17.225±9.792 respectively, and the percentages of Z7-12：Ac, Z9-14：Ac and Z11-16：Ac were 58.75±9.429, 18.91±7.539 and 22.34±7.209. Field trials indicated that each single component of sex pheromone was non-effective and captured no males. The lures baited with duality compound of AB （3 ： 1） had a certain attraction to males, the mean captured number was 2.6. The attraction ability of the lures baited with ternary compound of ABC （3 ： 1 ：1） to males added significantly, the mean captured number per trap was 7.40, which was 2.8 times of duality compound of AB （3 ： 1）. The contents of sex pheromone could obviously affect its capture ability to males, the mean captured number was the highest at the dosage of 200 μg.

气相色谱-负化学源质谱联用法测定水产品及食用油中氟乐灵的残留量

建立了一种可用于水产品及食用油中氟乐灵残留量分析的分散型固相萃取-气相色谱-负化学离子源质谱方法。水产品及食用油经乙腈提取，4℃冷藏后，采用分散型固相萃取法净化，由气相色谱-负化学离子源质谱选择离子监测技术进行测定与确证，同位素内标法定量。在1～40μg / L 范围内氟乐灵农药的线性关系良好；方法定量限（LOQ）为0.02μg / kg；对鳗鱼、烤鳗、梭子蟹、小龙虾、猪油和橄榄油等6种复杂基质进行1.0、2.0和3.0μg / kg 等3个水平的添加回收试验，平均回收率均处于80％～100％之间，RSD≤10.3％；无干扰现象出现。该方法可作为水产品及食用油中氟乐灵残留检测的确证方法。

Gas phase ion-molecule reactions of buckminsterfullerene C_(60) with some small organic compounds in mass spectrometer

In chemical ionization mass spectrometry (CIMS) gas phase C60+ or C60can react with fragment ions from three chloromethane and four multichloroethane molecular ions via ion-molecule reactions A dozen of gas-phase adduct ions of C60 are observed, and most of them contain chlorine atoms The results of the comparison and analysis show that the relative intensities of adduct ions are not directly proportional to the corresponding fragment ions in the MS of reagents,which implies that some fragment ions containing radicals are more reactive with C60+ or C60. This indicates that the alkene-like C60+ or C60 can act as a radical sponge in addition reactions.