If you would like to be kept up to date with our latest blogs, join our mailing list.
We value your privacy, so we never share our mailing list with third parties.
Latest Blogs
Raw Material testing – Implementation of Compendial Tests
Take, for example, the average Butterworth Laboratories Ltd in-house method for chromatographic impurities, which is typically around 7 pages long and has over 2000 words. The method will include important sections like Quality Control to ensure that it continues to operate within its validated parameters and specific instrument parameters that have been validated on the […]
Read More
Viscosity measurement, what would Newton think? Part 2
In part one of our viscous Newtonian explorations, I examined kinematic or capillary viscosity measurement and briefly discussed a Newtonian liquid. In this part, we will examine sample preparation and rotational or apparent viscosity. One of the main causes of Out-of-Specification results when testing solid samples is sample preparation issues. These can be further divided […]
Read More
Viscosity measurement, what would Newton think? Part 1
Viscosity determination can cause many problems, mainly due to misunderstandings of the various techniques, such as measurement conditions, settings and units. Let’s see if we can shed some light on the subject. The pharmaceutical, consumer healthcare and cosmetic industries frequently use excipients to ensure their products have the right thickness to ensure correct flow through […]
Read More
Karl Fischer, simple but complex
Karl Fischer’s (KF) water determination is a vital and well-established method, but it can be fraught with difficulties and complexities. A material’s water content is often used to correct assays or other tests to give results on an anhydrous basis. So, no matter how good the assay itself is, the whole analysis may be compromised […]
Read More
The Real Helium Crisis May Not Be What We Are Constantly Told
As an old chromatography guy, I am certainly no helium expert; I always understood the ‘Helium Crisis’ from only a GC perspective. I found useful information published in our favourite chromatography magazines and many articles from analytical column, GC and gas generator manufacturers discussing technical aspects of substitution with hydrogen. I knew that Helium was […]
Read More
Hypromellose and other cellulose-type assays
For decades, Butterworth has been using hydriodic acid in the form of the Zeisel reaction to strip themethoxy, ethoxy and hydroxypropoxy groups off various cellulose backbones. The assay ofhypromellose, methyl-, ethyl- and hydroxypropyl cellulose type samples to the Ph.Eur., USP, JP andChP involves a complex and hazardous reaction via the adipic acid catalysed cleavage of […]
Read More
The Background to Residual Solvent Analysis at Butterworth Laboratories Limited
1996 saw the implementation of the first automated headspace GC system in response to increased client requirements. Much of this testing in accordance with USP <467> Organic Volatile Impurities, however, was “blind compliance” since the 7 targeted solvents, including Benzene, were practically never used in the production of pharmaceutical articles and other solvents known to […]
Read More
No more burned fingers and the roots of residual solvent analysis at Butterworth Laboratories Limited (BLL)
I burnt my fingers this morning, removing my breakfast from a jammed toaster. After many years of gas chromatography, I am not unfamiliar with the occasional blister. When I arrived at the lab, someone shared a copy of a 30-year-old photo of David Bell, who made the most significant personal contribution to the development of […]
Read More
Recycled fire suppressant specifications – is there a case for revision?
Having arrived in the chromatography laboratory at Butterworth’s in September 1994, the first work I was assigned was the determination of the purity of fire suppressant gases. The analysis was to be performed using a Carlo Erba HRGC 5300 GC equipped with a gas sampling valve. Over the next 15 years, I would develop a […]
Read More
Let’s put the TLC back into TLC
Have we stopped appreciating this chromatographic technique? Perhaps we have, especially those under the age of 40. With the advent of computerised chromatography data systems (CDS) controlling advanced pieces of instrumentation, GC, HPLC, IC, et al., there does appear to be a somewhat unfair dismissal of TLC as the aforementioned chromatography techniques’ inferior sibling. Those […]
Read More
Thoughts from Christmas Past
It was 1991, and I had arrived at Berridge Environmental Laboratories in Chelmsford, hot off the train from Edinburgh, where I had just completed a 5-year joint honours degree. As shared in previous Blogs, I was being mentored by Dennis, a semi-retired elderly gentleman with a shock of white hair and asbestos fingers from all […]
Read More
Fundamentals of GC Method Development
It was 1991 and I had arrived at Berridge Environmental Laboratories in Chelmsford, hot off the train from Edinburgh where I had just completed a 5-year joint honours degree. As shared in previous Blogs, I was being mentored by Dennis, a semi-retired elderly gentleman with a shock of white hair and asbestos fingers from all […]
Read More
A Reminder of the Importance of Excipient Testing
In our April News Bulletin, we highlighted an Article and White Paper written by our Associate Director, John Welch on the importance of the testing of excipients used in the manufacture of medicines. In both of these publications, John referenced the example of cough syrup which was manufactured by an Indonesian company between 2021 and […]
Read More
Helium crisis revisited
Are we on the cusp of a helium crisis? There are many examples of scientists predicting that global helium reserves will be depleted in 20 to 35 years but we don’t believe this is credible. The Mineral Commodities Summaries 2023, produced by the US Geological Survey, part of the US Department of the Interior, reports […]
Read More
Are Ambient Temperatures in the UK Becoming a Risk Factor?
Ambient temperatures in the UK are not something we usually associate as a potential risk factor. But as a weather map from the summer of 2022 illustrates, is this something we should be taking more notice of? Butterworth is used to receiving samples from clients in packaging containing temperature monitors for samples that must be […]
Read More
Early eluters go with the flow, late eluters are driven by temperature
It was 1991 and I had arrived at Berridge Environmental Laboratories in Chelmsford, hot off the train from Edinburgh where I had just completed a 5-year joint honours degree. As shared in previous Blogs, I was being mentored by Dennis, a semi-retired elderly gentleman with a shock of white hair and asbestos fingers from all […]
Read More
Contamination of Drug Components and Products with Ethylene Glycol and Diethylene Glycol
At the start of May 2023, the FDA published a new Guidance for Industry document; Testing of Glycerin, Propylene Glycol, Maltitol Solution, Hydrogenated Starch Hydrolysate, Sorbitol Solution, and other High-Risk Drug Components for Diethylene Glycol (DEG) and Ethylene Glycol (EG). My own research on this subject has been very limited, however, three things are clear. […]
Read More
Would you like salt and vinegar on your chips?
The answer is NO if the chips are mounted on a printed circuit board (PCB). Manufacturers of PCBs have long understood the correlation between surface cleanliness and corrosion, electrochemical migration, dendritic growth and the resultant, current leakage, and shorting. This means that clean room technology utilised by the industry is very stringent and far exceeds […]
Read More
The Heart and the Achilles Heel of Gas Chromatography
It was 1991 and I had arrived at Berridge Environmental Laboratories in Chelmsford, hot off the train from Edinburgh where I had just completed a 5-year joint honours degree. As shared in my last Blog, I was being mentored by Dennis, a semi-retired elderly gentleman with a shock of white hair and asbestos fingers from […]
Read More
The USP, JP and Ph.Eur Chromatographers Sing in Perfect Harmony!
Christmas came early this year for chromatographers. After a 30 year career-long wait, on 01/12/2022, the USP General Chapter <621>Chromatography, and the JP Chromatography General Chapter were finally fully harmonised with the Ph Eur. General Chapter 2.2.46 Chromatographic Separation Techniques. The good news includes that allowable adjustments of chromatographic conditions, which were especially complex for […]
Read More
The continuing story of the impending redundancy of packed GC columns goes back a long way.
It was 1991 and I had arrived for my first day at Berridge Environmental Laboratories in Chelmsford, hot off the train from Edinburgh where I had just completed a 5 year joint honours degree. This was to be the first day of my being paid as a chromatographer. I reported to the team leader of […]
Read More
Exhaustive Extraction Doesn’t Need to Take a Lifetime or Cost the Earth
Polymeric artificial human joints are an example of a permanent contact medical devices. Since such devices are routinely sterilised using ethylene oxide (EO) after manufacture, it is a requirement of ISO 10993-7 to determine the lifetime average daily release of the resultant EO residues. This is calculated by dividing the total residue mass determined in […]
Read More
Helium supply may not be the only factor in the expansion of the use of Hydrogen Carrier Gas
We are now seeing so many articles talking about the move to Hydrogen as the default carrier gas that it has become an industry in its own right. When budding chromatographers ask me when this will happen, my usual reply is “When the pharmacopeia say so”. The type of carrier gas is not an allowable […]
Read More
Helium supply uncertainty and the expected long term transition to Hydrogen gas for use as chromatography and mass spectroscopy carrier
The finite nature and recent shorter-term supply uncertainties for Helium, have once again given rise to many articles with regard to its future use. Much helpful literature is available from instrument manufacturers addressing the changes to instrument hardware and chromatographic conditions required when substituting Helium with Hydrogen as carrier gas. The manufacturer’s example chromatograms using […]
Read More
Helium Crisis?
According to many sources, the storm clouds of yet another Helium shortage are gathering. This can be confirmed by the number of commentaries and graphs delivered by a simple Google search, including many which are conflicting in detail.
Read More
No More Blue Fingers – Butterworth Pass the Amino Acid Test
is the preferred process to separate free amino acids, the resolved sample components can’t be detected with the required sensitivity using UV or other common universal liquid chromatography detectors.
Read More