Toluene in Methanol (Derivative Spectroscopy) (265-270 nm)
What Are Cookies
You can prevent the setting of cookies by adjusting the settings on your browser (see your browser Help for how to do this). Be aware that disabling cookies will affect the functionality of this and many other websites that you visit. Disabling cookies will usually result in also disabling certain functionality and features of the this site. Therefore it is recommended that you do not disable cookies.
The Cookies We Set
When you submit data to through a form such as those found on contact pages or comment forms cookies may be set to remember your user details for future correspondence.
Third Party Cookies
This site uses Google Analytics which is one of the most widespread and trusted analytics solution on the web for helping us to understand how you use the site and ways that we can improve your experience. These cookies may track things such as how long you spend on the site and the pages that you visit so we can continue to produce engaging content.
For more information on Google Analytics cookies, see the official Google Analytics page.
From time to time we test new features and make subtle changes to the way that the site is delivered. When we are still testing new features these cookies may be used to ensure that you receive a consistent experience whilst on the site whilst ensuring we understand which optimisations our users appreciate the most.
Hopefully that has clarified things for you and as was previously mentioned if there is something that you aren't sure whether you need or not it's usually safer to leave cookies enabled in case it does interact with one of the features you use on our site. However if you are still looking for more information then you can contact us through one of our preferred contact methods:
0.020% v/v solution of toluene in methanol, permanently sealed by heat fusion into a far UV quartz cell. Supplied with a methanol blank.
In derivative spectroscopy, absorption spectra aretransformed into first-, second- or higher-order derivatives.This technique facilitates the resolution of two or more peaksthat overlap and become merged into a composite curve, andare represented by shoulders on that curve rather than asindividual peaks. By calculating the derivative, the underlying individual spectra can be more readily identified. Probably themost used is the second order, i.e d2 A/dλ2.
When this reference material is scanned in 2nd derivative mode against the methanol blank, the resulting spectrum should be similar to that shown, with a small negative extremum. ( ) at 285 nm between two larger negative extrema at 261 nm and 268 nm.
To meet the requirements of the Pharmacopoeia, the ratio A/B should be greater than 0.2: