Non-target environmental analysis by liquid chromatography/high-resolution mass spectrometry with a product ion and neutral loss database.

Despite the increasing detection of emerging substances in the environment, the identity of most are left unknown due to the lack of efficient identification methods. We developed a non-target analysis method for identifying unknown substances in the environment by liquid chromatography/high-resolution mass spectrometry (LC/HRMS) with a product ion and neutral loss database (PNDB). The present analysis describes an elucidation method with elemental compositions of the molecules, product ions, and corresponding neutral losses of the unknown substance: (1) with the molecular formula, possible molecular structures are retrieved from two chemical structure databases (PubChem and ChemSpider); then (2) with the elemental compositions of product ions and neutral losses, possible partial structures are retrieved from the PNDB; and finally, (3) molecular structures that match the possible partial structures are listed in order of number of hits.

Discovery of novel halogenated polycyclic aromatic hydrocarbons in urban particulate matters: occurrence, photostability, and AhR activity.

Halogenated aromatic compounds (HACs) in the environment have created great concern because of the associated adverse health implications. In this study we investigated the atmospheric behavior and exposure risk of brominated polycyclic aromatic hydrocarbons (BrPAHs) larger than three rings which were associated with particles in the urban air in Japan, and which were discovered as novel HACs in the air. Furthermore, the ambient levels of chlorinated polycyclic aromatic hydrocarbons (CIPAHs) and PAHs, in addition to BrPAHs, were also simultaneously investigated to emphasize the differences.

Chlorinated polycyclic aromatic hydrocarbons in the atmosphere: seasonal levels, gas-particle partitioning, and origin.

Ambient concentrations of 26 chlorinated polycyclic aromatic hydrocarbons (CIPAHs) with 2- to 5-rings were investigated in a Japanese urban city from December 2004 to December 2005. All the targeted CIPAHs were detected in either the gaseous or particulate phase. During the study, the ambient (gaseous + particulate) concentration of total CIPAH ranged from 18 to 330 pg m(-3).

Dichlorodiphenyltrichloroethane suppresses neurite outgrowth and induces apoptosis in PC12 pheochromocytoma cells.

It is well known that dichlorodiphenyltrichloroethane (DDT) is used as an insecticide and prevents many people in the tropical zone from devastating malaria. On the other hand, a number of reports have indicated that it may act as an endocrine disruptor and also has possible carcinogenic effects. However, the effects of DDT on the neural cells remain to be investigated.