Page 21 - Application Handbook - Liquid Chromatography
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C190-E181






                      Table 1  List of the major species contained in a phospholipid standard mixture, cow’s milk sample and a plasma sample
                                        Standard mixture         Cow’s milk sample          Plasma sample                                                      Stop- ow Comprehensive Two-dimensional
                    PL class        m/z          FAs          m/z         FAs          m/z          FAs
                                   [M−H] −                   [M−H] −                  [M−H] −                                      Technical                   Liquid Chromatography Combined with Mass
                                    831.5      16:1/18:2     835.5       16:0/18:1    885.5    18:0/20:4, 18:1/20:3
                                    833.5      16:0/18:2     859.5       18:3/18:0                                                 Report
                 Phosphatidylinositol  835.5   16:0/18:1     861.5   18:0/18:2, 18:1/18:1                                                                      Spectrometric Detection for Phospholipid Analysis
                      (PI)
                                    857.6   16:0/20:4, 18:2/18:2  863.5  18:0/18:1                                                                             LC×LC for phospholipids in milk and plasma samples
                                    859.5      18:2/18:1     887.5       20:3/18:0
                                    861.5   18:0/18:2, 18:1/18:1
                                                                                                                                                               Paola Dugo , Nermeen Fawzy , Francesco Cacciola , Paola Donato , Filomena Cichello , Luigi Mondello 1, 2
                                                                                                                                                                                                                       1
                                                                                                                                                                      1, 2
                                                                                                                                                                                   1
                                                                                                                                                                                                 1
                                                                                                                                                                                                           1
                                   [M+H] +                   [M+H] +                  [M+H] +
                                    744.5      18:0/18:2     690.6       14:0/18:1    744.5    18:1/18:1, 18:0/18:2
                                                             692.5       16:0/16:0    764.6       16:0/22:6
                                                             716.6   16:0/18:2, 16:1/18:1  768.5  18:0/20:4
                                                             718.6       16:0/18:1    792.5       18:0/22:6                        Abstract:
               Phosphatidylethanolamine                      742.6       18:2/18:1
                     (PE)                                    744.6   18:1/18:1, 18:0/18:2                                          A  novel  comprehensive  two-dimensional  liquid  chromatographic  (LC×LC)  system  for  characterization  of  phospholipid  (PL)  molecular  species
                                                             746.6       18:0/18:1                                                 belonging to six phospholipid classes was developed. To tackle such a task, a silica hydrophilic interaction liquid chromatography (HILIC) column
                                                             766.7       18:1/20:4                                                 was used as the ”rst dimension (D1), and reversed-phase liquid chromatography (RP-LC) with a C18 column was used as the second dimension
                                                             768.5       18:1/20:3                                                 (D2) in combination with mass spectrometric detection. Fraction transfer from the D1 to the D2 was performed by means of a two-position
                                                             770.6       18:0/20:3                                                 ten-port  switching  valve,  operated  under  stop-–ow  conditions.  The  capability  of  the  investigated  LC×LC  approach  was  demonstrated  in  the
                                                             792.5       18:0/22:6                                                 separation of phospholipid molecular species contained in two Folch-extracted cow’s milk and plasma samples.
                                   [M+H] +                   [M+H] +                   n.d.         n.d.                           Keywords: comprehensive LC, phospholipids, mass spectrometry, stop- ow
                                    788.6      18:0/18:2     786.5       18:2/18:1
                 Phosphatidylserine  790.6     18:0/18:1     788.5       18:0/18:2
                     (PS)           836.6      16:0/20:3     790.6       18:0/18:1
                                    838.6      16:0/20:2
                                    840.5      16:1/20:0
                                                                                                                                   1. Introduction
                                                                                                                                                                                      2. Experimental
                                                                                                                                   1. Intr oduction                                   2. Experimental
                                   [M+H] +                   [M+H] +                  [M+H] +
                                    732.5      16:0/16:1     706.6       16:0/14:0    885.5    18:0/20:4,18:1/20:3                                                                    2-1. Samples and sample preparation
                                    758.6      16:0/18:1     720.5       15:0/16:0                                                 Phospholipids (PLs) are an important class of biomolecules playing an
                                    760.5      16:0/20:4     732.5       16:0/16:1                                                 important  functional,  structural  and  metabolic  role  in  the  human
                                    782.5      18:2/18:2     734.5       16:0/16:0                                                 body as witnessed by recent studies which have given considerable   A crude cow’s milk sample was provided by a Calabrian producer
                                    784.5      18:1/18:2     746.5       15:0/18:1                                                 evidence on the health-promoting effects such as antiin–ammatory   whereas the plasma sample was kindly donated by a sane volunteer.
                                    786.5      18:1/18:1     748.6       15:0/18:0
                 Phosphatidylcholine  788.5    18:0/18:1     756.5       16:0/18:3                                                 activity and risk reduction of cardiovascular diseases.   Extraction of the lipid fraction was carried out from 10 mL and 1.5
                     (PC)           790.5      18:1/22:6     758.6       16:0/18:2                                                 Several analytical methods have been developed for characterization of   mL, respectively, of the cow’s milk and plasma sample, according to
                                    792.6      18:0/22:6     760.5       16:0/18:1                                                                                                    the Folch method in order to attain an exhaustive extraction of the
                                    806.5      18:2/20:4     762.5       16:0/18:0                                                 molecular species within different PL classes. From a chromatographic
                                    810.5      18:2/20:2     774.5       17:0/18:1                                                 stand-point, it must be noted that the employment of a single tech-  whole lipid content. The total extract was evaporated under vacuum,
                                    818.6      20:1/22:6     782.5       18:2/18:2                                                 nique can only provide useful information on either the different phos-  and the ”nal dry residue (400 and 150 mg for cow’s and donkey’s
                                    834.6      18:0/20:4     784.6       18:1/18:2                                                 pholipid classes or the molecular species within a particular PL class.  milk, respectively) was re-dissolved in chloroform/methanol 2:1 (v/v)
                                    836.6      18:0/22:5     786.6   18:0/18:2, 18:1/18:1
                                                             788.6       18:0/18:1                                                 In this technical report, in order to simultaneously separate and identify   and stored at –18 °C until use.
                                                                                                                                   the different PL classes together with the separation and identi”cation of
                                   [M+H] +                   [M+H] +                  [M+H] +
                                    703.6        16:0        675.6        14:0        675.5        14:0                            the different molecular species within each class, a fully comprehensive
                                    705.6        18:0        689.5        15:0        701.5        18:1                            LC  (LC×LC)  method  was  developed  for  the  ”rst  time.  Such  a  system
                                    731.5        18:0        703.6        16:0        703.5        16:0                            comprised  of  a  silica  hydrophilic  interaction  liquid  chromatography
                                                             705.6        16:0        729.5        18:1
                                                             759.5        20:0        731.5        18:0                            (HILIC) column in the ”rst dimension (D1) and an octadecylsilica column
                  Sphingomyielin                                                                                                   in the second dimension (D2) and was run under stop-–ow conditions.
                     (SM)                                    773.5        21:0        759.6        20:0
                                                             785.6        22:1        785.6        22:1                            The capability of such a system (Fig. 1) was evaluated for analysis of PLs
                                                             787.6        22:0        787.5        22:0                            contained in two Folch-extracted cow’s milk and plasma samples (Fig. 2).
                                                             799.6        23:1        811.5        24:2
                                                             801.5        23:0        813.5        24:1
                                                             813.5        24:1        815.5        24:0
                                                             815.5        24:0

                                                                                                First Edition: December, 2015


                                             For Research Use Only. Not for use in diagnostic procedures.
                                             The content of this publication shall not be reproduced, altered or sold for any commercial purpose without the written approval of Shimadzu.   Fig. 2  Enlargement of the HILIC×RP-LC–ESI-MS contour plot for
                                             The information contained herein is provided to you "as is" without warranty of any kind including without limitation warranties as to its      separation of the phosphatidylethanolamine (PE),
                                             accuracy or completeness. Shimadzu does not assume any responsibility or liability for any damage, whether direct or indirect, relating to the
                                             use of this publication. This publication is based upon the information available to Shimadzu on or before the date of publication, and subject   Fig. 1  LC×LC/MS instrumentation  along with the corresponding 2D raw data
                                             to change without notice.
       www.shimadzu.com/an/                                                                      © Shimadzu Corporation, 2015      1 University of Messina, Italy
                                                                                                                                   2 Chromaleont S.r.l.                                                                                   1
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