CAS numbers consist of three numbers separated by dashes. The first comprises of two to seven digits, the second is two digits and the third is one digit. The last number is, in fact, a check digit for the rest of the code. It's simple to check if a CAS number contains an error by calculating a checksum as follows: …

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It's relatively easy to extract CAS numbers from a PDF. I've used this to scrape chemical catalogs, subsequently using the CAS numbers to look up additional information through PubChem. CAS numbers are easier to scrape than most other chemical information, such as name, formula or catalog number, as they follow a …

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Here's an example of using R to extract tabular content and metadata from a series of pdf files and push the data into a single table. The concept is fairly straightforward - read in PDF and convert to text, parse each line and use regular expressions to extract pertinent information. Three types of data are returned: …

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There seems to be a fad right now of merchandising articles containing words made up of chemical symbols. Beryllium Erbium (BeEr) is particularly popular and I have to admit I have a T-Shirt claiming "Call me NErDy". I've put together a small code in R which will check to see if a word can be created purely …

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