Multi-element standard for nuclear magnetic resonance spectroscopy
Organic compounds which contain nitrogen, fluorine, and phosphorus atoms together with carbon atoms and hydrogen atoms and which can be used as a multi-element standard for 1 H—, 13 C—, 15 N—, 19 F—, and 31 P nuclear magnetic resonance spectroscopy. Also, a nuclear magnetic resonance spectroscopy method, preferably a quantitative nuclear magnetic resonance spectroscopy method, using said compounds and a method for qualitatively and/or quantitatively determining an analyte using such a nuclear magnetic resonance spectroscopy method.
1. A method of identifying an analyte wherein the method comprises:
providing a standard compound for nuclear magnetic resonance spectroscopy, the standard compound comprised of the formula (1) or (2)
where R 1 is a phenyl radical or benzyl radical whose benzene ring has the following substituents:
at least one —CF 3 substituent,
at least one nitrogen-containing substituent selected from —NO 2 and —NR 4 R 5 , where R 4 and R 5 independently of one another are selected from H, CH 3 , and CH 2 CH 3 , optionally one or two substituents selected from Cl, Br, I, —CH 3 , and —C(═O)OR 6 , where R 6 is selected from H, CH 3 , and CH 2 CH 3 , and
at least one hydrogen atom, where at least one of the hydrogen atoms is ortho to at least one substituent selected from —NO 2 and —C(═O)OR 6 , and
where R 2 and R 3 are the same as R 1 or independently of one another are selected from H, CH 3 , and CH 2 CH 3 ;
detecting the nuclear magnetic resonance of one of the atoms 1 H, 13 C, 15 N, 19 F, or 31 P; and
determining the analyte quantitatively.
2. The method according to 1 , wherein the benzene ring carries precisely two hydrogen atoms as substituents.
3. The method according to claim 2 , wherein the two hydrogen atoms are meta to one another on the benzene ring.
4. The method according to claim 1 , wherein at least one hydrogen atom on the benzene ring is ortho to at least one CF 3 substituent or CH 3 substituent.
5. The method according to claim 1 , wherein at least two hydrogen atoms on the benzene ring are ortho to at least one CF 3 substituent or CH 3 substituent.
6. The method according to claim 1 , wherein at least two hydrogen atoms on the benzene ring are ortho to at least one substituent selected from —NO 2 and —C(═O)OR 6 .
7. The method as claimed in claim 1 , wherein the benzene ring carries only one hydrogen atom as substituent, and the hydrogen atom on the benzene ring is preferably ortho to at least one CF 3 substituent or CH 3 substituent.
8. The method according to claim 1 , wherein, in a 1 H nuclear magnetic resonance spectroscopy, with the chemical shift of tetramethylsilane set as 0 ppm, the chemical shift δ of at least one hydrogen atom on the benzene ring is at least 8 ppm.
9. The method as claimed in claim 8 , wherein the spin-lattice relaxation time T 1 of the at least one hydrogen atom having the chemical shift of at least 8 ppm is not more than 5 s.
10. The method according to claim 8 , wherein the chemical shift of two hydrogen atoms on the benzene ring is at least 8 ppm, and the relaxation times of the two hydrogen atoms differ by at least 3 s.
11. The method according to claim 1 , wherein the compound is selected from the compounds having the formulae (3) to (8):
where the radicals R 2 and R 3 independently of one another are selected from the phenyl radical or benzyl radical shown in the respective formulae, H, CH 3 , and CH 2 —CH 3 , preferably from the phenyl radical or benzyl radical, H, and CH 3 .
12. The method according to claim 11 , wherein the compound is selected from the following compounds:
13. A method of identifying an analyte wherein the method comprises:
providing a standard compound for nuclear magnetic resonance spectroscopy, the standard compound comprised of the formula (9)
detecting the nuclear magnetic resonance of one of the atoms 1 H, 13 C, 15 N, 19 F, or 31 P; and
determining the analyte quantitatively.