11. Derivatization reactions involving solid-phase reagents or derivatization on a solid support

Solid-phase reagents are polymeric materials with specific groups that are reactive and can be transferred to the analyte molecule producing derivatization. For an analyte of the form Y:H, the reaction with a solid-phase reagent can be written as follows:

$$\text{Y:}\\\text{H} + \text{R-Polymer} \rightarrow \text{R}-\text{Y} + \text{H-Polymer} \tag{39}$$

polydimethylsiloxane (PDMS) fiber containing o-(2,3,4,5,6-pentafluorobenzyl) hydroxylamine hydrochloride as a reagent. After exposing the fiber to the air sample contaminated with formaldehyde, the derivatization agent reacts with formaldehyde absorbed onto the coating forming an oxime. The oxime is thermally

desorbed in a GC injector port and analyzed by GC with ECD [33].

Derivatization Methods in GC and GC/MS DOI: http://dx.doi.org/10.5772/intechopen.81954

\* and Victor David2

© 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

1 R.J. Reynolds Tobacco Co., Winston-Salem, NC, USA

2 University of Bucharest, Bucharest, Romania

provided the original work is properly cited.

\*Address all correspondence to: moldovs@rjrt.com

Author details

39

Serban C. Moldoveanu<sup>1</sup>

Solid-phase reagents must work analogously to the corresponding smallmolecule reagents containing the group R (a tag). Reagents that are insoluble in certain solvents at high concentrations can often provide a high ratio of analyte/ substrate in a polymeric microenvironment that yields a high kinetic rate for the heterogeneous reaction.

A variety of materials can be used as solid support, such as specifically bound reagents on a silica support (used, e.g., for online derivatization in HPLC analysis), ion exchange resins, as well as other supports [31]. One example of solid-phase support that can produce derivatization is trifluoroacetyl nylon 6,6. This solidphase reagent can be obtained from poly(hexamethylene adipamide) (nylon 6,6) and trifluoroacetyl anhydride. This solid-phase reagent can be used in amine derivatization in a reaction as follows:

$$\begin{array}{ccccc} \mathsf{R}^{\mathsf{a}} & \mathsf{O} & & & \\ \mathsf{N}^{\mathsf{a}} & \mathsf{N}^{\mathsf{a}} & \cdots & \mathsf{C} - (\mathsf{CH}\_{2})\_{\mathsf{4}} - \mathsf{C} - \mathsf{N} - (\mathsf{CH}\_{2})\_{\mathsf{6}} - \mathsf{N} \cdots & \mathsf{N}^{\mathsf{a}} & \mathsf{N}^{\mathsf{a}} & \cdots & \mathsf{C} - \mathsf{CF}\_{2} \\ & \mathsf{R}^{\mathsf{b}} & \mathsf{O} & \mathsf{COCF}\_{3} & \mathsf{COCF}\_{3} & & \mathsf{R}^{\mathsf{b}} & \mathsf{O} & \end{array} \qquad \begin{array}{ccccc} \mathsf{R}^{\mathsf{a}} & \mathsf{O} & & & \\ \mathsf{N}^{\mathsf{a}} & \mathsf{O} & & & \\ \mathsf{N}^{\mathsf{a}} & \mathsf{O} & & & \\ \mathsf{N}^{\mathsf{a}} & \mathsf{O} & & & \\ & & & & \end{array} \tag{40}$$

This derivatization of the amine is done by mixing the solid-phase reagent with a solution of amine solution in CH3CN. Following derivatization, the solid-phase reagent is separated by centrifugation, and the solution is concentrated by evaporating part of the solvent and analyzed by GC (an amine internal standard must be used in this procedure). However, some such derivatizations require a long time of interaction between the solid-phase reagent and the analytes and found only limited applications.

(Another) alternative of derivatization of specific analytes is using the reaction between the reagent and the analyte both adsorbed on a solid support. This type of derivatization has been used, for example, in connection with a solid-phase microextraction (SPME) technique [32]. In this technique a reagent is initially adsorbed in the SPME fiber, followed by exposure to the analytes. The derivatized analytes are further desorbed in the injection port of the GC and analyzed using a detector such as MS. For example, formaldehyde from air can be analyzed using a

Derivatization Methods in GC and GC/MS DOI: http://dx.doi.org/10.5772/intechopen.81954

Numerous other types of derivatization reactions were used for making the

various cyclic types of compounds such as azines, siliconides, boronates, etc., that are thermally stable and do not have polar hydrogens such that GC or GC/MS analysis is possible. In addition to reagents that add specific moieties to the

analytes, oxidation and reduction were sometimes used for the analyte modification

Solid-phase reagents are polymeric materials with specific groups that are reactive and can be transferred to the analyte molecule producing derivatization. For an analyte of the form Y:H, the reaction with a solid-phase reagent can be

Solid-phase reagents must work analogously to the corresponding smallmolecule reagents containing the group R (a tag). Reagents that are insoluble in certain solvents at high concentrations can often provide a high ratio of analyte/ substrate in a polymeric microenvironment that yields a high kinetic rate for the

A variety of materials can be used as solid support, such as specifically bound reagents on a silica support (used, e.g., for online derivatization in HPLC analysis), ion exchange resins, as well as other supports [31]. One example of solid-phase support that can produce derivatization is trifluoroacetyl nylon 6,6. This solidphase reagent can be obtained from poly(hexamethylene adipamide) (nylon 6,6) and trifluoroacetyl anhydride. This solid-phase reagent can be used in amine

This derivatization of the amine is done by mixing the solid-phase reagent with a

(Another) alternative of derivatization of specific analytes is using the reaction between the reagent and the analyte both adsorbed on a solid support. This type of

solution of amine solution in CH3CN. Following derivatization, the solid-phase reagent is separated by centrifugation, and the solution is concentrated by evaporating part of the solvent and analyzed by GC (an amine internal standard must be used in this procedure). However, some such derivatizations require a long time of interaction between the solid-phase reagent and the analytes and found only limited

derivatization has been used, for example, in connection with a solid-phase microextraction (SPME) technique [32]. In this technique a reagent is initially adsorbed in the SPME fiber, followed by exposure to the analytes. The derivatized analytes are further desorbed in the injection port of the GC and analyzed using a detector such as MS. For example, formaldehyde from air can be analyzed using a

<sup>Y</sup>:<sup>H</sup> <sup>þ</sup> <sup>R</sup>‐Polymer ! <sup>R</sup> � <sup>Y</sup> <sup>þ</sup> <sup>H</sup>‐Polymer (39)

ð40Þ

analytes suitable for GC and GC/MS analyses. These include formation of

Gas Chromatography - Derivatization, Sample Preparation, Application

11. Derivatization reactions involving solid-phase reagents or

derivatization on a solid support

(see, e.g., [4]).

written as follows:

heterogeneous reaction.

applications.

38

derivatization in a reaction as follows:

polydimethylsiloxane (PDMS) fiber containing o-(2,3,4,5,6-pentafluorobenzyl) hydroxylamine hydrochloride as a reagent. After exposing the fiber to the air sample contaminated with formaldehyde, the derivatization agent reacts with formaldehyde absorbed onto the coating forming an oxime. The oxime is thermally desorbed in a GC injector port and analyzed by GC with ECD [33].
