101 

 Use of a greater collision energy enhanced the abundance of fragments relative to 



the parent [M-H]~ ion; although the relative intensities among fragment (daughter) 



ions were not altered. The daughter ions are formed by neutral losses of small 



molecules. The most abundant daughters are due to the loss of formic acid (46 Da) 



and carbon dioxide (44 Da) to produce ions at m/z 43 and m/z 45, respectively. The 



process by which these losses can occur will be described later in the discussion of 



a later figure. Additional neutral losses found in the daughter spectrum include 



losses of carbon monoxide (28 Da) and water (18 Da) to form the ions at m/z 61 and 



m/z 71, respectively; there is a low abundance of m/z 59, corresponding to loss of 



formaldehyde (30 Da). The ion at m/z 87 is formed by the elimination of Hj (2 Da) 



from deprotonated lactic acid. 



The daughters of the m/z 87 ion, obtained under identical conditions (to that 



for daughters of m/z 89), are presented in figure 3-2. It is interesting to note the 



similarity in fragmentation patterns found in daughter spectra of this ion and the [M- 



H]~ ion in figure 3-1. The labeling of masses in figure 3-2 remains consistent with 



the representation of lactic acid as the neutral parent of all these species. Therefore, 



the parent ion for daughter analysis in this case is the [M-H-H2]"" ion of lactic acid 



at m/z 87. The most abundant fragment ion is now the species corresponding to a 



neutral loss of CO2 (at m/z 43) from the parent ion. Although still present, the loss 



of formic acid producing the ion at m/z 41 is significantly decreased, as are the ions 



at m/z 57 and m/z 59, corresponding to losses of formaldehyde and carbon monoxide 



