Analysis hydrophilic interaction

We use the second-dimension separation from Fig. 6.6 with a 25 pL injection volume and 2.5 min sampling time the separation is an RPLC method that uses a monolithic column. Thus, 10 pL/min is the maximum flow rate in the first-dimension. Fig. 6.7 shows the development of the first-dimension column that utilizes a hydrophilic interaction (or HILIC) column for the separation of proteins at decreasing flow rates. The same proteins were separated in Fig. 6.6 (RPLC) and 6.7 (HILIC) and have a reversed elution order, which is known from the basics of HILIC (Alpert, 1990). It is believed that HILIC and RPLC separations are a good pair for 2DLC analysis of proteins as they appear to have dissimilar retention mechanisms, much like those of NPLC and RPLC it has been suggested that HILIC is similar in retention to NPLC (Alpert, 1990). Because the HILIC column used in Fig. 6.7 gave good resolution at 0.1 mL/min and no smaller diameter column was available, the flow was split 10-fold to match the second-dimension requirement... 

Van Nuijs ALN, Tarcomnicu I, Bervoets L, Blust R, Jorens PG, Neels H, Covaci A (2009) Analysis of dmgs of abuse in wastewater by hydrophilic interaction liquid chromatography-tandem mass spectrometry. Anal Bioanal Chem 395 819-828... 

Direct injection of plasma or supernatant after protein precipitation on a short column with a high liquid flow rate is a common method for reducing analysis time in the pharmaceutical industry. The direct injection of a sample matrix is also known as the dilute-and-shoot (DAS) approach.62 DAS can be applied to all types of matrices and approaches and is the simplest sample preparation method with matrix dependency. Direct injection can also be approached through the extraction of eluent from PPT, SPE, and LLE onto a normal phase analytical column. The procedure is called hydrophilic interaction liquid chromatography (HILIC)70110111 and it avoids the evaporation and reconstitution steps that may cause loss of samples from heat degradation and absorption. 

An interesting approach was proposed in Lobinski s group for the analysis of non-covalent Ni species in biological samples.49 The Ni species in aqueous plant tissue extracts were quantitative determined by SEC-ICP-MS in combination with ESI-ToFMS/MS after purification of Ni species by hydrophilic interaction HPLC (HILIC).49... 

Naidong W, Eerkes A (2004) Development and validation of a hydrophilic interaction liquid chromatography-tandem mass spectrometric method for the analysis of paroxetine in human plasma. Biomed Chromatogr 18 28-36... 

DelTAversano, C., Eaglesham, G., Quilliam, M.A. (2004). Analysis of cyanobacterial toxins by hydrophilic interaction liquid chromatography-mass spectrometry. J. Chromatogr. A 1028 155-64. 

Gika, H.G., Theodoridis, G.A., and Wilson, I.D., Hydrophilic interaction and reversed-phase ultra-performance liquid chromatography TOF-MS for metabonomic analysis of Zucker rat urine, J. Sep. Sci., 31(9), 1598, 2008. 

Figure 3.14. Diagrams showing the bonding chemistry used in Waters XTerra columns, (a) XTerra MS C8 The use of tri-functional bonding reagent with two or three attachment points leads to more acid resistance and less column bleed for LC/MS analysis, (b) XTerra RP8 The use of bonding reagent with an embedded-polar group (carbamate) leads to some shielding of the residual silanols as well as different selectivity due to additional hydrophilic interactions with the solutes. Diagram courtesy of Waters Corporation.

Troyer JK, Stephenson KK, Fahey JW. Analysis of glucosinolates from broccoli and other cruciferous vegetables by hydrophilic interaction liquid chromatography. J Chromatogr A 2001 991 299-304. 

Shin-ichi K, Analysis of impurities in streptomycin and dihydrostreptomycin hy hydrophilic interaction chromatog-raphy/electrospray ionization quadrupole ion trap/time-of-flight mass spectrometry. Rapid Commun. Mass Spectrom. 2009 23(6) 907-914. 

Application of LC-MS to the analysis of aminoglycosides has also been problematic, due to the low retention of the parent compounds on the reversed phase columns commonly used. To fry to resolve this problem, ionpairing reagents, such as fluorinated acids, have been used. The introduction of hydrophilic interaction liquid chromatography (HILIC) has provided an alternative means for the retention and separation of aminoglycosides prior to mass specfromefric determination (see Chapter... 

Tolstikov, V. V. Fiehn, .Analysis ofhighlypolar compounds of plant origin combination of hydrophilic interaction chromatography and electrospray ion trap mass spectrometry. Anal. Biochem. 2002, 301, 298-307. 

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