Drugs are substances, natural or man-made, taken into the body that cause psychological or physical alteration to the consumer (Saferstein). However, most processed drugs look the same, either colourless or some other colour; this is where drug analysis comes in. Drug analysis is the process of using various methods to examine and investigate the components of a suspected substance (Saferstein). One of the methods used is Capillary Zone Electrophoresis/ time of flight Mass Spectrometry (CE-MS). In all fields of Forensic Science various substances are found and collected from crime scenes and not all of them can be identified using simple analytical methods, so, scientists needed to come up with much more sophisticated and updated methods.
Drug analysis is a huge part of Forensic Science and everyday new methods are tested to find out which ones are more effective and efficient. A recent research study was designed, by a group of scientists, to determine how effective the use of CE-MS is in the forensic analysis of drugs using different stable buffers, for example, Phosphate, Borate and Tris.
The CE-MS experiment was designed to determine if the composition and concentration of a substance influences how efficient its components separate when non-volatile buffers are used at different ph. This technique uses a combination of Capillary Electrophoresis and Mass Spectrometry. It makes use of charges in an electric field through capillary tubes and the movement of ions through the sample to cause separation (Gottardo, Miksik and Aturki). The experiment was applied by analysing the hair samples of drug users.
Sample collection for this experiment was done by cutting a substantial amount of hair samples from the scalp and processed using the CE-MS method. The hair samples were washed, cut into pieces, incubated overnight at 45 Degrees Celsius with an amount of Hydrochloric Acid. After, the mixture was neutralized with Sodium Hydroxide and the organic phase is extracted, evaporated and dried thoroughly and mixed with water and used with different buffers at different ph. The sample is then separated using Capillary Electrophoresis to separate the components using high electric fields to break the components apart. Then, they are identified by using mass spectrometry to identify their structures and names using mass-to-charge ratios. The results were collected and graphed to compare efficiency.
The CE-MS experiment has its effectiveness; it is temperature controlled because of the use of capillary tubes. Also, this process is effective when the sample is at low concentrations because of its efficiency and high speed, and the experiment was designed effectively to make sure there was no contamination from outside sources. Even though the experimental design has its advantages there are disadvantages too. Only a few researchers have been successful in presenting using only organic buffers and the experiment did not make use of a control experiment. This experiment would have been better if it was done by using samples from different regions and testing using different age groups.
After the sample was analysed, it was seen that the addict had traces of a lot of different drugs including cocaine and methadone, which is used in detoxification treatment. This new method of drug analysis has positive and negative feedback. The CE-MS experiment design provides a good environment for the components of the sample to efficiently separate and this is due to the perpendicular capillary tubes. Also, the design method only needs a small amount of sample to work. On another note the structure of the design method is sensitive and any slight change in pH and or temperature can alter results. Also, not a lot of research has been done on this experiment and several runs are necessary for accuracy. Instrument-wise the sample can stick to the walls of the capillary tube, and the mass spectrometer cannot determine exactly what the compound is but just the class it is in. When volatile buffers are involved, separation is not a good choice since defocusing occurs and through research it was found that using organic buffers like Phosphate, Borate and Tris causes suppression of the analyte’s ionization and end up contaminating the results. Using different buffers give different results and the authors proved that when they tested them on their samples. They found out that the lower the pH the more effective the buffer because it improved the ionization and made the experiment efficient
Compared to other methods like High Performance Liquid Chromatography-Mass Spectrometry (HPLC-MS) which can analyse highly volatile substances, CE-MS can only analyse using stable buffers. Scientists have been researching ways to make CE-MS more efficient when working with volatile buffers to make it more efficient and to make the resolution high, unfortunately, the separation process does not always end as expected so multiple runs must be made. Also, when dealing with organic buffers CE-MS is better than HPLC-MS in terms of buffering capacity, easier transferability of methods and better efficiency (Gottardo, Miksik and Aturki). And, when aligned with Liquid Chromatography, CE only uses small amounts of the sample and, separation-wise, only has a low buffer flow rate.
The experiment design’s aim was to determine if CE-MS is effective in the determination of the components of a sample using non-volatile buffers, the sample was hair collected from drug users and analysed. The experiment was a success and the components of drugs used were separated and identified using inorganic buffers. The authors found out that using inorganic buffers were better than organic ones because of efficiency and their high tolerance. This is a huge success for Forensic Science because under controlled conditions the experiment is easily done and efficient (the good outweighs the bad). CE-MS is suitable for drug analysis when the samples are not standardized, and the sample is not contaminated by outside sources. Also, combining both Capillary Zone Electrophoresis and Mass Spectrometry is good because in a single analytic experiment one can have high separation efficiency and molecular mass information (Saferstein).