Traditional blood testing methods are not good enough to meet the fast pace of technological change that has made our lives steadfast. Diagnostic laboratories take a long time to detect different components in extremely complex mixture of blood. Amino acids in blood have always been a challenge because of the significant differences in their chemical structures. Also, detectability has always acted as a difficult task for analysts to solve, that calls for a need of a special and advanced techniques like gas chromatography, liquid chromatography and capillary electrophoresis. However, the invention of highly sensitive GC detectors has made quantification and chromatography of blood odors directly without derivatization.
EST Inc. has invented a new type of portable gas chromatograph called the zNose® which is capable of performing analytical measurements of volatile organic vapors and odors in near real time with part per trillion sensitivity. The zNose® segregate and quantifies the organic chemistry of odors through ultra-high speed chromatography within 1 minute.
By classifying the amino acids by molecular weights, the odor chemistry of blood could be evaluated. Also, other physical properties, such as vapor pressure or boiling point could also be used to estimate the chemical signature of blood odors.
Using zNose®, a blood sample was tested. Following are the blood odor measurements:
- The solid-state detector directly measured odor intensity of blood samples vs elution time from a GC column, which was temperature programmed from 40o C to 160o C at 10o C per second.
- Sensitivity was controlled by the temperature of the detector (20o C) and the amount of the vapor sampled (15 mm).
- Extracting and pre-concentrating a 15-milliliter vapor sample from the vial measured the concentration of chemical vapors from one drop of blood to be measured in less than one minute.
- The odor chemistry measurement results are compared in three vertically offset chromatogram traces corresponding to two blood samples and the headspace vapors from a vial containing the amino acid standards.
-With few exceptions, the odor chemistry of un-derivatized blood matches that of the amino acid standards and from this experiment it is concluded that the major odor producing chemicals in blood are in fact the amino acids.
zNose® provides olfactory images, called VaporPrints™, that are high-resolution 2-dimensional images based upon the relative concentrations of the individual chemical that make an odor. Odors from sampled blood and amino acid were identified and juxtaposed using chromatograms and visual, olfactory images based upon chemical measurements. And the simple amino acids which are the building blocks of proteins in the blood were found to be the major volatile chemicals.
Hence, odor measurement can be done easily with speed and accuracy using zNose® as it is based upon the science of gas chromatography. Also, The ability to rapidly perform analytical measurements on blood and other biological samples in real time provides researchers with a cost-effective new tool for monitoring volatile organic compounds associated with biological samples such as blood and urine. This electronic nose acts as a helping hand for the diagnostics and renders speed, accuracy and precision without derivatization. Also, its picogram sensitivity acts as a useful tool for the studies of bio-chemical and metabolic processes involving volatile organics of all kinds.