Direct injection analysis

He, J., Shibukawa, A., Nakagawa, T., Wada, H., Fujima, H., Imai, E., Go-oh, Y. (1993). Direct injection analysis of atenolol enantiomers in plasma using an achiral/chiral coupled column HPLC system. Chem. Pharm. Bull. 41, 544—548. 

Jemal M. et al., 1999. A versatile system of high-flow high performance hquid chromatography with tadem mass spectrometry for rapid direct-injection analysis of plasma samples for quantitation of a /1-lactam drug candidate and its open-ring biotransformation product. Rapid Commun Mass Spectrom 13 1462. 

Figure 4.11 Direct injection analysis of haemoglobin in red blood cells. Column, Asahipak ES-502C eluent, 32 min linear gradient from 25% 30 mM sodium phosphate buffer to 65% 30 mM sodium phosphate containing 300 mM sodium chloride pH 5.5 flow rate, 1.0 ml min-1 detection, 425 nm. Samples. A, normal subject and B, diabetic patient.

Sanbe H, Haginaka J (2003) Restricted access media-molecularly imprinted polymer for propranolol and its application to direct injection analysis of beta-blockers in biological fluids. Analyst 128(6) 593-597... 

Direct injection analysis for iron, manganese, copper, and cadmium... 

To achieve structural and semi-quantitative information on the anthocyanins ESI-MS/MS direct-injection analysis of extract can be performed. An example of an ESI-MS spectrum is reported in Figure 3.16. 

Jemal, M. Ouyang, Z. Xia, Y.-Q. Powell, M.L. A Versatile System of High-Flow High Performance Liquid Chromatography with Tandem Mass Spectrometry for Rapid Direct-Injection Analysis of Plasma Samples for Quantitation of a p -Lactam Drug Candidate and its Open Ring Biotransformation Product, Rapid Commun. Mass Spectrom. 13(14), 1462-1471 (1999). 

M. Goto, N. Nakamura and D. Ishii, Micro high-performance liquid chromatographic system with micro precolumn and dual electrochemical detector for direct injection analysis of catecholamines in body fluids, J. Chromatogr, 226, 33 42 (1981). 

Sudo, Y. Akiba, M. Sakaki, T. Takahata, Y. Glyceiylalkylsilylated sUica gels for direct injection analysis of drugs in serum by high-performance Uquid chromatography. J.Liq.Chromatogr., 1994,17, 1743— 1754 [direct injection serum extracted phenoharhital, phenytoin]... 

He, J. Shibukawa, A. Nakagawa, T. Direct injection analysis of carbeunazepine and its active 10,11-epoxide metabolite in plasma by use of a semipermeable surface (SPS) silica column in LC. 

Santasania, C.T. Direct injection analysis of diuretic and sinti-inflammatory drugs on a shielded hydro-phobic phase column. J.Liq.Chromatogr, 1990, 13, 2605-2631 [direct injection serum gradient horse extracted hydrochlorothiazide, oxyphenbutazone, phenylbutazone]... 

Bidart, M. Lesgards, G. Direct injection analysis of 6p-hydroxycortisol and cortisol in urine by HPLC-UV with on-line IRSP column. J.Liq.Chromatogr., 1995, 18, 725-738... 

H. Yoshida, I. Morita, G. Tamai, T. Masujima, T. Tsuru, N. Takai and H. Imai, Some characteristics of a protein-coated ODS column and its use for the determination of drugs by the direct injection analysis of plasma samples, Chromatographia, 1984, 19, 466-472. 

Y.M. Li, S.X. Jiang and L.R. Chen, Direct Injection Analysis of Hexamethylene Bisacetamide in Biological Fluids by an HPLC Column-Pitching Technique with a Micellar Mobile Phase, Chromatographia, 34 63 (1992). 

This buffer was also used with 40 mM sodium bisulfite for the post column reaction solution. The concentration range was 0.05-40 pg/mL with detection limits of 0.025 pg/mL. One potential disadvantage to the direct injection analysis is the longterm buildup of uneluted plasma constituent (water is a very weak solvent). 

However, in spite of its deduced advantages, direct injection analysis was found to have a major drawback associated to the detection of those less concentrated or weakly sensitive compounds (Perez-Parada et al. 2012). 

---