There are some clear advantages to using electrospray ionization mass spectrometry as an analytical method. One advantage is its ability to handle samples that have large masses. Another advantage is that this ionization method is one of the softest ionization methods available, therefore it has the ability to analyze biological samples that are defined by non-covalent interactions. A quadrupole mass analyzer can also be used for this method, which means that a sample's structure can be determined fairly easily. The m/z ratio range of the quadrupole instrument is fairly small, which means that the mass of the sample can be determined to with a high amount of accuracy. Finally, the sensitivity for this instrument is impressive and therefore can be useful in accurate quantitative and qualitative measurements.