HPLC-atmospheric pressure chemical ionization mass spectrometry

HG Fouda, RP Schneider. Quantitative determination of the antibiotic azithromycin in human serum by high-performance liquid chromatography (HPLC)-atmospheric pressure chemical ionization mass spectrometry Correlation with a standard HPLC-electrochemical method. Ther Drug Monitor 17 179, 1995. 

Wissiack, R. and Rosenberg, E., Universal screening method for the determination of US environmental protection agency phenols at the lower ng 1 level in water samples by online SPE-HPLC-atmospheric pressure chemical ionization mass spectrometry within a single run, J. Chromatogr. A, 963, 149-157, 2002. 

Stanaszek R, Piekoszewski W. 2004. Simultaneous determination of eight underivatized amphetamines in hair by high-performance liquid chromatography-atmospheric pressure chemical ionization mass spectrometry (HPLC-APCI-MS). J Anal Toxicol 28 77. 

McCarry et al. [19-25] performed a similar series of HPLC fractionations to determine the PAHs in sediment samples. They observed C24H14 LPAHs similar to those found by Wise and co-workers in a coal-tar SRM. In later work, LPAHs of 26, 28, 30, and 32 carbons were found. Both a DAD and direct atmospheric-pressure chemical-ionization mass spectrometry were used for detection. To make the DAD less specific and more universal, the average response from 250 nm to 370 nm was collected as a total-absorbance chromatogram. 

Detection methods HPLC-DAD, HPLC with diode-array detection. HPLC-(ESI-MS), HPLC with electrospray ionization mass spectrometry. RP-HPLC, revcrsed-phase HPLC. UPLC/Q-TOFMS, UPLC with quadrupole-time of flight mass spectrometry. HPLC-APCI-MS, HPLC with atmospheric pressure chemical ionization mass spectrometry. CE-IT-MS, capillary elecliophoresis-ion-1r mass spectrometry. LC-ESI-ITMS, liquid chromatography-electrospray ionization ion trap mass spectrometry. LC-ELSD, LC with evaporative light scattering detector. DNBZ-Cl, 3,5-dinitrobenzoyl chloride. 

The purity of heptakis(2,3,6-tri-0-methyl)-P-CD preparations was checked by reversed-phase (RP)-HPLC using the isocratic mobile phase, methanol-water 85/15, v/v. Analytes were detected by atmospheric pressure chemical ionization-mass spectrometry (APCl-MS). The measurements illustrated that the purity of the CD derivatives markedly influences the enantioselectivity of the preparation. 

A selective analytical method based on HPLC, combined with atmospheric pressure photoionization (APPI) mass spectrometry, has been developed for the simultaneous determination of NTV and DON. A liquid chromatography/atmospheric pressure chemical ionization mass spectrometry (LC/APCI-MS) method based on time-of-flight MS (TOF/MS) with a real-time reference mass correction technique was also developed for the simultaneous determination of Fusarium mycotoxins (NIV, DON, fusarenon-X, 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol, HT-2 toxin, T-2 toxin, diacetoxyscirpenol, ZEN) and Aspergillus mycotoxins (ailatoxin Bl, aflatoxin B2, aflatoxin Gl, aflatoxin G2) in com, wheat, cornflakes, and biscuits [112]. 

For confirmatory assay, liquid chromatography-tandem mass spectrometry (LC-MS/MS) is becoming more frequently used in the analysis of OTC owing to its high sensitivity and ability. Electrospray ionization (ESI) [55-57] and atmospheric pressure chemical ionization (APCI) [41] methods combined with tandem mass spectrometry are favored because of their higher sensitivity and better reproducibility. Hamscher et al. [58] developed a method for the determination of persistent TC residues in soil fertilized with manure by HPLC tandem mass spectrometry, MS-MS, and confirmation by MS-MS-MS. Zhu et al. [59] developed an LC-tandem mass spectrometry for the analysis of common tetracyclines in water. The detection limit for oxytetracycline was 0.21 pg/L. Lykkeberg et al. [60] used LC-MS/MS for determination of oxytetracycline and its impurities EOTC, TC, ETC, ADOTC, oc-AOTC, and /i-AOTC. 

X. Xu, A.M. van der Craats, E.M. Kok and P.C.A.M. de Bruyn, Trace analysis of peroxide explosives by high performance liquid chromatography — atmospheric pressure chemical ionization — tandem mass spectrometry (HPLC-APCl-MS/MS) for forensic applications ,... 

Notes LOD, limit of detection MeOH, methanol EtOH, ethanol ACN, acetonitrile EtAC, ethyl acetate SPE, solid phase extraction HLB (hydrophilic lipophilic balanced) TFA, trifluoroacetic acid GC, gas chromatography TMS, trimethylsilyl MS, mass spectrometry HPLC, high-performance liquid chromatography DAD, diode array detector NMR, nuclear magnetic resonance ESI, electrospray ionization APCI, atmospheric pressure chemical ionization CE, capillary electrophoresis ECD, electrochemical detector CD, conductivity detector TLC, thin layer chromatography PDA, photodiode array detector. 

For abbreviation of analyte names see Sect. Abbreviations . ACN acetonitrile, APCI atmospheric pressure chemical ionization, dial, microdialysis samples, ESI electrospray ionization, FA formic acid, iso isocratic, IT ion trap, lin range linear range, MeOH methanol, MRM multiple reaction monitoring, MS full scan mass spectrometry, n.s. not specified, OAc acetate, QqQ triple quadrupole mass spectrometer, SIM selected ion monitoring, Solv HPLC solvent, SQ single quadrupole mass spectrometer, T temperature Ratios given as v/v... 

Strege summarized the technique of high-performance liquid chromatography-electrospray ionization mass spectrometry (HPLC-ESI-MS) in dereplication of natural products. In contrast to earlier electron impact ionization (El), ESI technique is applicable to virtually any ion in solution with a soft ionization process. A comparison of ESI with fast atom bombardment (FAB), matrix assisted laser desorption ionization (MALDI), atmospheric pressure chemical ionization (APCI) and other techniques demonstrates its superior sensitivity, compatibility and reliability when coupled with HPLC [51]. 

Today, mass spectrometry offers an attractive alternative as a detector to HPLC. Newer techniques for linking HPLC systems with mass spectrometers directly via atmospheric pressure chemical ionization (APCI) and electrospray interfaces should see an expansion of this analytical tool in the analysis of confectionery fats, a field in which it has not yet been applied. Triacylglycerols... 

A variety of MS formats are widely accepted and applied in the pharmaceutical industry. The specific MS application is often defined by the sample introduction technique. The pharmaceutical applications highlighted in this article feature two types of sample introduction techniques dynamic and static. Dynamic sample introduction involves the use of high-performance liquid chromatography (HPLC) on-line with MS. The resulting liquid chromatography/mass spectrometry (LC/MS) format provides unique and enabling capabilities for pharmaceutical analysis. The electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) modes are the most widely used. Static sample introduction techniques primarily use matrix-assisted laser desorption/ionization (MALDI). ... 

The detection and identification of phenolic compounds, including phenolic acids, have also been simph-fied using mass spectrometry (MS) techniques on-hne, coupled to the HPLC equipment. The electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) interfaces dominate the analysis of phenohcs in herbs, fmits, vegetables, peels, seeds, and other plants. In some cases, HPLC, with different sensitivity detectors (UV, electrochemical, fluorescence), and HPLC-MS are simultaneously used for the identification and determination of phenolic acids in natural plants and related food products.In some papers, other spectroscopic instmmental techniques (IR, H NMR, and C NMR) have also been apphed for the identification of isolated phenolic compounds. 

HPLC with MS detection is commonly employed as an alternate detector to UV. Mass spectrometry is generally regarded as a universal detector, but the response per unit weight depends greatly on the ionization type (e.g., positive or negative electrospray, atmospheric pressure chemical ionization, etc.) and on the ionization efficiency of the analyte under the given conditions. 

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