| Low-molecular-mass aldehydes（LMMAs）are a group of reactive carbonyl contaminants,which are well-known for their toxicity,mutagenicity and carcinogenicity,due to their abilities to cross-link with important biomolecules,such as nucleic acids and proteins.Accordingly,the analysis of LMMAs with high sensitivity and high selectivity is of significant importance.However,the detection of LMMAs is often hindered by their intrinsic properties,such as high volatility,hydrophilicity and lack of chromophores or fluorophores.Therefore,derivatization is generally prerequisite before detection.In our previous study,it was found that the aminooxy reagents could efficiently label LMMAs through their aldehyde groups,under mild conditions to produce derivatives with good instrumental responses.Under this circumstance,new derivatization methods were developed using two new aminooxy derivatization reagents,4-（（aminooxy）methyl）-6-ethyl-7-hydroxy-2H-chromen-2-one（AMHC）and 4-（4-（aminooxy）butyl）-7-（1-（（2R,3R,4S,5S,6R）-3,4,5-trihydroxy-6-（hydroxymethyl）tetrah-dro-2H-pyran-2-yl）-1H-1,2,3-triazol-4-yl）-2H-chromen-2-one（AHPC）,respectively.The methods were then applied for the analysis of LMMAs by highly sensitive detection,including high performance liquid chromatography with fluorescence detection（HPLC-FLD）and liquid chromatography-tandem mass spectrometry detection（LC-MS/MS）（nano LC-quadrupole-orbitrap-MS）,respectively.Our main work was described as follows:（1）A fluorescent derivatization reagent AMHC was synthesized and characterized for the analysis of 3 furfurals（2-furaldehyde,5-methyl-2-furaldehyde and 5-hydroxymethyl-2-furaldehyde）.A pre-column derivatization was established.Combined with HPLC-FLD,a highly sensitive method for the determination of 3furfurals was achieved and was successfully applied to analyze infant food samples with satisfactory accuracies（recoveries in the range of 96.70-99.95%）,the contents of furfurals in the samples were in the range of 43.24-258.52μg/100 g.This method has several merits as high sensitivity（detection limits are in the range of 0.4-0.8 n M）,mild reaction condition,high derivatization efficiency（≥97.9%）and in avoidance of complicated extraction or enrichment procedures,making it an ideal way for furfurals detection in food samples.（2）AMHC was further applied for the analysis of 9 saturated fatty aldehydes（formaldehyde,acetaldehyde,propionaldehyde,butyraldehyde,valeraldehyde,hexanal,heptaldehyde,octanal and nonanal,C1-C9）,combined with LC-MS/MS method.A new derivatization strategy was optimized and applied to analyze C1-C9in indoor dust samples.All aldehydes were successfully detected with satisfactory recoveries,ranging 94.47 to 111.46%.The contents of 9 aldehydes in the samples were in the range of 0.307-5.493 mg/100 g,respectively.Our method is highly sensitivity（detection limits are in the range of 0.15-0.30 n M）and robust,which can be further applied for the monitoring of aldehyde levels in environmental samples.（3）New stable isotope-coded reagents(12C-AHPC and 13C-AHPC)were used to analyze 4-hydroxynonenal（4-HNE）.After a detailed optimization of the derivatization reaction conditions,a relative-quantitative method of 4-HNE was achieve by MS.The proposed method was successfully applied to the determination of 4-HNE in two kinds of red wines with high sensitivity and low matrix interference.It is expected to be used for the relative quantitative analysis of 4-HNE and other unsaturated aldehydes in a large number of real samples in the future. |
