Lai-Lai Yan

Peking University, Beijing, Beijing Shi, China

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Publications (5)4.11 Total impact

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    Biological trace element research 05/2012; · 1.92 Impact Factor
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    ABSTRACT: In order to explore the associations between trace elements in dietary intake and the other three biological media (blood, urine, or feces) and inter-element interactions among the latter, we simultaneously collected 72-h diet duplicates, whole blood, and 72-h urine and feces from 120 free-living healthy males in China. Correlations among the toxic (cadmium [Cd], lead [Pb]), and nutritionally essential (zinc [Zn], copper [Cu], iron [Fe], manganese [Mn], selenium [Se], iodine [I]) elements were evaluated using Spearman rank correlation analysis based on analytical data determined by inductively coupled plasma-mass spectrometry. Dietary Cd intakes were highly correlated with the fecal Cd and blood Cd levels. Inverse correlations were found for Fe–Cd and Fe–Pb in both diet versus blood and diet versus feces. Cd–Zn and Cd–Se were significantly directly correlated in the urine and feces. Cd–Se and Pb–Se were negatively correlated in blood. In addition, there existed an extremely significant association between urinary Se and urinary I. Moreover, the other two highly direct correlations were found for Se–Fe and for I–Fe in urine. Improved knowledge regarding their mutual associations is considered to be of fundamental importance to understand more the complex interrelationships in trace element metabolism. KeywordsToxic and essential elements–Metal–metal correlation–ICP-MS–Dietary intake–Urinary excretion–Fecal excretion
    Biological Trace Element Research 02/2012; 145(2):127-135. · 1.31 Impact Factor
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    ABSTRACT: In the present study, a method for determination of BrO3- and Br- using ion chromatograghy coupling with inductively coupled plasma mass spectrometry (IC-ICP-MS) was developed. BrO3- and Br- were separated on a Hamilton PRP X-100 (150 x 4.1 mm, 10 microm) column guarding with a On-guard II RP (4 x 50 mm) column with 10 mmol x L(-1) NH4NO3 eluent solution at 2 mL x min(-1). By using 200 microL sample loop, the detection limits for BrO3- and Br were 0.35 and 0.36 microg x L(-1), respectively. BrO3- had good linearity in the range 4.8-160.0 ng x L(-1). The standard solution linear equation was y = 250.31x-45.43, and R2 = 0.9999. Br had good linearity in the range 4.2-140.0 ng x L(-1). The standard solution linear equation was y = 186.84x-127.10, and R2 = 0.9994. Recoveries of spiked samples were 98.9%-109.5% and 97.4%-106.1%, respectively. The samples included various kinds of Chinese patent drugs, waters, and beverages. Among them, 14 bottled drinking waters and 2 kinds of tap waters were found containing BrO-, while other samples were under BrO3- detection limit. Br- was detected in all samples.
    Guang pu xue yu guang pu fen xi = Guang pu 11/2010; 30(11):3136-9. · 0.29 Impact Factor
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    ABSTRACT: In the present study, a method for determination of BrO-3 and Br- using ion chromatograghy coupling with inductively coupled plasma mass spectrometry (IC-ICP-MS) was developed. BrO-3 and Br- were separated on a Hamilton PRP X-100(150×4.1 mm, 10 μm)column guarding with a On-guard RP(4×50 mm)column with 10 mmol·L-1 NH4NO3 eluent solution at 2 mL·min-1. By using 200 μL sample loop, the detection limits for BrO-3 and Br- were 0.35 and 0.36 μg·L-1, respectively. BrO-3 had good linearity in the range 4.8 -160.0 ng·L-1. The standard solution linear equation was y=250.31x-45.43, and R 2=0.999 9. Br- had good linearity in the range 4.2-140.0 ng·L-1. The standard solution linear equation was y=186.84x-127.10, and R 2=0.999 4. Recoveries of spiked samples were 98.9%-109.5% and 97.4%-106.1%, respectively. The samples included various kinds of Chinese patent drugs, waters, and beverages. Among them, 14 bottled drinking waters and 2 kinds of tap waters were found containing BrO-3, while other samples were under BrO-3 detection limit. Br- was detected in all samples.
    Guang pu xue yu guang pu fen xi = Guang pu 01/2010; 30(11). · 0.29 Impact Factor
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    ABSTRACT: Fine particulate matters (PMZ2.5) collected in Beijing during a period from September 2005 to May 2006 were studied. Sequential extraction procedures were applied to divide the total lead into three fractions, i.e. water soluble, liposoluble and insoluble lead. Lead concentrations and their isotopes in each fraction were then determined by inductively coupled plasma mass spectrometry (ICP-MS). Lead standard reference GBW 09133 was used to investigate the accuracy of lead concentration determination and SRM 981 was used to correct the mass discrimination and instrumental drift. The obtained results showed that the analytical precision of lead isotope ratios for SRM 981 of seven repeat measurements at lead concentration of 10 ng x mL(-1) came to about 0.34, 0.27 and 0.24 percent for the 206 Pb/204 Pb, 206Pb/207 Pb and 206Pb/208 Pb ratios, respectively. In Beijing, the mass concentrations for PM2.5 and lead of ambient air were 125.556 and 0.5415 microg x m(-3) respectively for winter 2005, and 201.6 and 0.475 microg x m(-3) respectively for spring 2006 on average, resembling those published results. It was indicated that the lead in the PM2.5 existed mainly in insoluble form, which accounted for 78.99%, while water soluble lead and liposoluble lead amount were 20.69% and 0.32%, respectively. The mean values of 206Pb/207Pb ratio for water soluble species and insoluble species were 1.152 6 +/- 0.009 3 and 1.219 3 +/- 0.009 1 respectively, with a significant difference (Student's test; p < 0.01) statically. By comparing 206Pb/207Pb ratios between biological specimen and ambient air samples, the 206Pb/207Pb ratios in water soluble fraction coincided very well with those in adult blood, therefore, water soluble lead but not insoluble lead in PM2.5 may be the potential source of adults blood lead in Beijing. More attention should be paid to the effect of soluble lead in fine particle matters on human health.
    Guang pu xue yu guang pu fen xi = Guang pu 03/2009; 29(2):515-8. · 0.29 Impact Factor