CAJ | 학술논문

为了更好地区分测量小分子芳香烃，利用一台Nd∶YAG激光器提供能量为0.085 J?cm －2、波长为266 nm的入射光。针对苯、甲苯、萘、菲、蒽、芘和屈不同环数的芳香烃，使用激光诱导荧光法研究了单一芳香烃及不同芳香烃混合物的荧光光谱。结果表明，芳香烃的苯环数是荧光发射光谱的主要决定因素；相同苯环数不同结构的芳香烃对荧光光谱范围基本没有影响；由于266 nm波长的吸收效率差异，导致相同环数的芳香烃的荧光光强存在差异；而且吸收效率相近且浓度相同时，环数越大，荧光光强越强。随着芳香烃环数的增加，荧光光谱波段和峰值都出现从紫外波段向可见光波段红移的现象，同时吸收效率相近时，荧光光谱范围变宽；一环至四环芳香烃的较好的荧光光谱区分范围分别为275～320，320～375，375～425和425～556 nm。针对不同芳香烃混合物研究表明，由于辐射能量传递机制导致混合物中有3环或4环芳香烃存在时，紫外波段的光被损失，所以1环或2环芳香烃混入混合物后，混合物中的1环或2环荧光光谱不能被检测到，但荧光光谱强度增大；当混合物中只包含3环和4环芳香烃时，荧光发射光谱具有两种芳香烃的特点；当混合物中存在3环和4环芳香烃时，荧光发射光谱和各自的浓度相关，从而可以一定程度区分不同环数物质。
위료경호지구분측량소분자방향경，이용일태Nd∶YAG격광기제공능량위0.085 J?cm －2、파장위266 nm적입사광。침대분、갑분、내、비、은、비화굴불동배수적방향경，사용격광유도형광법연구료단일방향경급불동방향경혼합물적형광광보。결과표명，방향경적분배수시형광발사광보적주요결정인소；상동분배수불동결구적방향경대형광광보범위기본몰유영향；유우266 nm파장적흡수효솔차이，도치상동배수적방향경적형광광강존재차이；이차흡수효솔상근차농도상동시，배수월대，형광광강월강。수착방향경배수적증가，형광광보파단화봉치도출현종자외파단향가견광파단홍이적현상，동시흡수효솔상근시，형광광보범위변관；일배지사배방향경적교호적형광광보구분범위분별위275～320，320～375，375～425화425～556 nm。침대불동방향경혼합물연구표명，유우복사능량전체궤제도치혼합물중유3배혹4배방향경존재시，자외파단적광피손실，소이1배혹2배방향경혼입혼합물후，혼합물중적1배혹2배형광광보불능피검측도，단형광광보강도증대；당혼합물중지포함3배화4배방향경시，형광발사광보구유량충방향경적특점；당혼합물중존재3배화4배방향경시，형광발사광보화각자적농도상관，종이가이일정정도구분불동배수물질。
In order to distinguish small aromatics preferably ,a Nd∶YAG Laser was used to supply an excitation laser ,which was adjusted to 0.085 J?cm -2 at 266 nm .Benzene ,toluene ,naphthalene ,phenanthrene ,anthracene ,pyrene and chrysene were used as the representative of different rings aromatics .The fluorescence emission spectra were researched for each aromatic hy‐drocarbon and mixtures by Laser induced fluorescence (LIF) .Results showed that the rings number determined the fluorescence emission spectra ,and the structure with same rings number did not affect the emission fluorescence spectrum ranges .This was due to the fact that the absorption efficiency difference at 266 nm resulted in that the fluorescence intensities of each aromatic hy‐drocarbon with same rings number were different and the fluorescence intensities difference were more apparently with aromatic ring number increasing .When the absorption efficiency was similar at 266 nm and the concentrations of each aromatic hydrocar‐bon were same ,the fluorescence intensities were increased with aromatic ring number increasing .With aromatic ring number in‐creasing ,the fluorescence spectrum and emission peak wavelength were all red‐shifted from ultraviolet to visible and the fluores‐cence spectrum range was also wider as the absorption efficiency was similar .The fluorescence emission spectra from one to four rings could be discriminated in the following wavelengths ,275 to 320 nm ,320 to 375 nm ,375 to 425 nm ,425 to 556 nm ,re‐spectively .It can be used for distinguish the type of the polycyclic aromatic hydrocarbons (PAHs) as it exists in single type .As PAHs are usually exist in a variety of different rings number at the same time ,the results for each aromatic hydrocarbon may not apply to the aromatic hydrocarbon mixtures .For the aromatic hydrocarbon mixtures ,results showed that the one‐or two‐ring PAHs in mixtures could not be detected by fluorescence as three‐or four‐ring PAHs existed in mixture .This was caused by ra‐diation energy transfer mechanism ,in which the ultraviolet light was lost in mixtures but the fluorescence intensities were in‐creased with the one‐or two‐ring PAHs adding .When the mixture only contained three‐and four‐ring PAHs ,the fluorescence emission spectrum showed the both characteristics of three‐and four‐ring PAHs fluorescence .When three‐and four‐ring PAHs existed in mixtures at the same time ,the fluorescence emission spectra were related to each concentration ,so the rings number could be discriminated to a certain extent .