Searching with Data Cartridges

Structure registration is the process of entering structural information in a centralized repository, usually a structure database. These repositories serve as a pool for providing structure information that has been created in other departments of a company. Structure databases are set up according to the individual needs of a department or company. They consist of a common representation of a structure in a standardized file format, such as MolFile, SDF, reaction (RXN) (MDL), JCAMP (International Union of Pure and Applied Chemistry), or simplified molecular input line entry specification. Any additional data can be stored with the structure depending on the context typical examples are structure properties, reaction conditions, and literature references. 

Since the external database might be used as a general repository, an ELN must also allow for registering structures and reactions created in an electronic document to avoid switching between different systems and reentering information. 

Searching for structures or reactions in an external repository is an alternative to entering the structure directly into the scientific document. This is especially helpful if the structure is complex and not easy to author. Another application is the search for structures stored in an external system — for instance, to find already performed identical or similar reactions. The search query is typically entered via commonly used structure editors that provide the required standard file format. The search query can be performed on individual databases or on all connected databases, including the internal one, at the same time. 

The results of a structure or reaction query are displayed in a hit list, ideally within an ELN software. The user can then create a new section in the electronic scientific document using any structure from the hit list, including metadata delivered by the database. By transferring the structure, an additional unique identifier from the external database needs to be kept that is, the created section has a hyperlink to the external system that allows opening the default structure viewer directly from the section. 

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Air samples were collected on Tenax TA (60-80 mesh) (0.5-1.0 1 total volume at a flow rate of 50 ml/min). The analysis of Tenax tubes was carried out using a GC/ MS-system (Hewlett-Packard 6890) or a GC/FID-system (Hewlett-Packard 5890) with a 25-m HP-5 column, each equipped with a thermal desorber - cold trap injector (Perkin Elmer ATD 400). Identification of the compounds was based on a PBM library search. Moreover, mass spectra and retention data were compared with those of reference compounds. The monoterpenes and sesquiterpenes were sampled on active charcoal (NIOSH standard, SKC 226-01, 60-80 1 total volume at a flow rate of 0.5 1/min). The terpenes were extracted by use of carbon disulfide under constant shaking for 1 h and analyzed via GC/FID. Aldehydes were trapped on filter cartridges coated with dini-trophenylhydrazine (DNPH) (Macherey Nagel). The dinitrophenylhydrazone derivatives were extracted with acetonitrile and analyzed via HPLC/UV. 

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