In the medical field, spectroscopy technology is being used for research into 470-year-old bones which may have relevance to modern-day sufferers of the bone condition rickets.
The technology helped scientists confirm that many sailors who died on Henry VIII’s warship Mary Rose had rickets in childhood. The vessel, the king’s flagship, sank in the Solent, off Hampshire, in 1545, resulting in the deaths of more than 400 men. Some of the sailors’ bones were analysed using Raman spectroscopy, a pioneering non-destructive laser technology, in an attempt to identify evidence of bone disease. Two sets of tibias were obtained from The Mary Rose Trust, some that appeared anatomically healthy and some that were abnormal in shape.
The deformations in the abnormal bones were suspected to be due to a metabolic bone disease such as rickets, which is caused by poor diet. The Raman study confirmed that the abnormally shaped bones did indeed have chemical abnormalities. The RAMAN study, led by Professor Allen Goodship, was funded as part of a £1.7 million grant from the Engineering and Physical Sciences Research Council and the bones were measured in a laser facility at the Institute of Orthopaedics UCL. The ‘normal’ bones that were analysed as part of the study were supplied by the Vesalius Centre at the University of Bristol.
At first glance, the research into a condition in drowned sailors 470 years ago may seem to have little relevance to modern day but, in fact, it may be more useful than it at first appears. According to the research team, the Raman technique may have a place in modern-day detection of the condition, which is of particular interest because of concerns that conditions such as rickets are making a comeback in some countries due to the effects of poverty. Dr Jemma Kerns, RAMAN Clinical Study Manager at UCL and RNOH, one of the scientists who conducted the study, said: “This is the first time that this laser technology has been used to study bone disease in archaeological human bone.
“We have identified chemical changes in the bones, without damaging them. There is strong evidence to suggest that many of the sailors had suffered from childhood rickets and we hope to apply the Raman technique to the study of modern day rickets.” Alex Hildred, Curator of Human Remains at the Mary Rose Trust, said: “The Mary Rose Trust has the responsibility for the remains of over 179 individuals who perished with the ship. “Their provenance is absolute; they represent the crew of an English warship in July 1545. The human remains have potential to make a contribution to the public through research, education, display and interpretation.”
What is a mass spectrometer?
A mass spectrometer is a an analytical instrument that measures the mass-to-charge ratio (m/z) of charged analytes (ions). Often the mass spectrometer, or downstream software, can determine the charge as well. Thus, the instrument can effectively provide mass measurements rather than m/z measurements. For example, if the instrument detects an ion of m/z 500 Daltons but it can be determined that the charge is 2+, then the mass (m) is 1000 Daltons. An important feature is that a modern mass spectrometers can measure many analytes simultaneously. Thus, complex mixtures of analytes can be introduced to the mass spectrometer at once. The mass spectrometer will analyze the mixture and output a mass spectrum showing a peak at each m/z that was detected. Scan times differ between instruments but the typical times to get a full mass spectrum range from 100 milliseconds up to a second. The range of masses that can be measured, the accuracy or the measurements, and the resolution that can be achieved vary greatly depending on the instrument. See the mass analyzer section for more details. The height of each peak is representative of how many ions are being detected at that particular m/z. These peaks are not directly quantitative; however, careful use of internal standards and references can provide quantitative information.
What are MS1 and MS2?
MS1 and MS2 refer to two very broad categories of MS scan types. One of the primary uses of mass spectrometry is to identify peptides and proteins. It is often not possible to do this by m/z measurement alone so commonly mass spectrometry methods involve fragmentation of petides and measurement of the of the resulting m/z ratios. Scans which measure m/z ratios without fragmentation are termed MS1 scans. Scans involving fragmentation are MS2 scans.
