title: Reductive amination of glutaraldehyde 2,4-dinitrophenylhydrazone using 2-picoline borane and high-performance liquid chromatographic analysis.
abstract: A typical method for the measurement of glutaraldehyde (GLA) employs 2,4-dinitrophenylhydrazine (DNPH) to form GLA-DNPhydrazone derivatives. However, this method is subject to analytical errors because GLA-DNPhydrazone is a quaternary bis-derivative and forms three geometric isomers (E-E, E-Z and Z-Z) as a result of the two C[double bond, length as m-dash]N double bonds. To overcome this issue, a method for transforming the C[double bond, length as m-dash]N double bond into a C-N single bond, using reductive amination of DNPhydrazone derivatives, has been applied. The amination reaction of GLA-DNPhydrazones with 2-picoline borane is accelerated with catalytic amounts of acid and is completed within 10 minutes in the presence of 100 mmol L(-1) phosphoric acid. Reduction of GLA-DNPhydrazone by 2-picoline borane is unique and results in the formation of N-(2,4-dinitrophenyl)-1-piperidinamine (DNPPA). NMR and LC-APCI-MS data confirmed the product identification. DNPPA is very stable and did not change when stored for at least four weeks at room temperature. DNPPA has excellent solubility of 14.6 g L(-1) at 20 °C in acetonitrile. The absorption maximum wavelength and the molar absorptivity of DNPPA were 351 nm and 4.2 × 10(4) L mol(-1) cm(-1) respectively. Complete separation between the reduced forms of C1-C10 aldehyde DNPhydrazones, including DNPPA, can be achieved by operating the reversed-phase high-performance liquid chromatograph at 351 nm in gradient mode using a C18 amide column. The reductive amination method for GLA overcomes analytical errors caused by E-E, E-Z and Z-Z geometrical isomers.
authors: Department of Environmental Health, National Institute of Public Health, Minami, Wako City, Saitama, Japan. uchiyama@niph.go.jp
authors: Shigehisa
authors: S
authors: Uchiyama
authors: Hironari
authors: H
authors: Sakamoto
authors: Akiko
authors: A
authors: Ohno
authors: Yohei
authors: Y
authors: Inaba
authors: Hideki
authors: H
authors: Nakagome
authors: Naoki
authors: N
authors: Kunugita
mesh_terms: D000586:Amination; D002851:Chromatography, High Pressure Liquid; D005976:Glutaral / Q000032:analysis* / Q000737:chemistry*; D006835:Hydrazones / Q000737:chemistry*
chemical_list: C001072:2,4-dinitrophenylhydrazone; D006835:Hydrazones; D005976:Glutaral