Study On Adsorbents For Selective Adsorption Of Harmful Components In Mainstream Cigaratte Smoke

"Tar harm reduction" of cigarette products is the key and difficult point in the research of Chinese tobacco field for a long time.In the aspect of the detection of harmful components in cigarette mainstream smoke,the current national and industrial standard methods are generally complicated,and the detection of some compounds is not comprehensive.As for harm reduction with adsorbent,only activated carbon is widely used in cigarette products as filter additives,application research of other adsorbents is not mature,and the study of the relationship between the nature of adsorbate and adsorbents and the adsorption efficiency of harmful components in smoke is also rarely reported.Accordingly,this paper established a detection method for polycyclic aromatic hydrocarbons(PAHs)in cigarette mainstream smoke,then studied on the adsorption efficiency of activated carbon and ?-cyclodextrin as filter absorbents for harmful components in cigarette mainstream smoke,at last,a kind of activated carbon which has efficiently adsorption of carbonyl and volatile organic compounds(VOCs)was selected as a adsorbent on the basis of the foregoing studies,a method was established for simultaneous capture and detection of carbonyl and VOCs in cigarette mainstream smoke by the adsorbent.The main contents and conclusions are as follows:(1)A method for detection of PAHs in cigarette mainstream smoke was established by optimizing the pretreatment conditions,the PAHs were trapped by Cambridge filters and ultrasonic extracted by cyclohexane,purified by SPE column,concentrated by evaporator,then detected by GC-MS The detection limits of PAHs is in the range of 0.05 ng cig-1 to 0.18 ng cig-1,the repeatabilities expressed as RSDs are less than 7.66%,the recovery rates are between 87.15%and 110.73%,so the method is suitable for detecting PAHs in cigarette mainstream smoke.Some Cigarette samples were detected using this method,it is found that the distribution ratios of PAHs in cigarette mainstream smoke of are similar although the samples are different brands.(2)Three kinds of activated carbons and ?-cyclodextrin were added separately to the filter,and the harmful release in the cigarette was detected.The results showed that the activated carbons adsorbent have good adsorption capacity for carbonyl compounds,VOCs and semi-VOCs,?-cyclodextrin has good adsorption capacity for phenolic compounds,semi volatile organic compounds and PAHs.Activated carbon and ?-cyclodextrin has good complementarity in the aspect of harm reduction.The structure of the activated carbons was characterized,and the correlations between the structure parameters of activated carbons and the properties of adsorbates and the adsorption efficiencies were discussed.It is found that when the pore size is close to the molecular diameter of the adsorbate,the activated carbon presents a good adsorption efficiency.Also,for?-cyclodextrin,the closer the diameters of adsorbate and ?-cyclodextrin are,the more easily the adsorbate adsorbed.For PAHs,carbonyl compounds,VOCs and semi-VOCs,the molecular radius of gyration is the most influential property parameter for the adsorption efficiency.For most compounds,the weaker the polarity is,the more easily it is to be adsorbed by activated carbon and ?-cyclodextrin,but carbonyl compounds do not adhere to this rule.For activated carbon,the higher the boiling point is,the more easily the adsorbate is to be adsorbed,and for ?-cyclodextrin,it is not conducive to adsorption either boiling point of the adsorbate is too high or too low.For phenolic compounds,the boiling point is the most influential property parameter for the adsorption efficiency.(3)Using 953 activated carbon as adsorbent,a method was established for simultaneous capture and detection of carbonyl compounds and VOCs in cigarette mainstream smoke by optimizing the pretreatment conditions,the use of 300 mg adsorbent can fully capture carbonyl compounds and VOCs,the target compounds in the adsorbent are extracted by oscillating extraction with methanol and carbon disulfide,part of the extract were detected by GC-MS for determination of VOCs,and part of the extract was detected by liquid chromatography for carbonyl compounds after derivatization.The detection limits is in the range of 0.01 ?g cig-1 to 0.11 ??g cig-1,the repeatabilities expressed as RSDs were less than 4.77%,the recovery rates is between 86.26%and 107.73%,so the method is suitable for detecting carbonyl compounds and VOCs in cigarette mainstream smoke.Compared with standards,this method greatly reduced the pretreatment time of samples and the organic reagent consumption,and saved the cost of detection because it can capture two types of compounds simultaneously in one suction process,without pre-dropping derivatization reagent on the Cambridge filters,also no need to build a cold trap hydrazine.