nlwxpearo
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 Posted: Thu 10:31, 10 Feb 2011 Post subject: Cosmetics safrole and 6 - methyl gas chromatograph |
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Cosmetics safrole and 6 - methyl gas chromatography - mass spectrometry
) Calculated: X = c ・ V / m (1) where: x samples of safrole or 6-methyl coumarin content, ~ g / g; c a standard curve of the sample solution Richard safrole or 6-methyl coumarin concentration, g / rIll; as the final solution volume, ml; m of a sample of the quality of, g. 2 Results and discussion 2.1 Sample pre-treatment methods used by experimental methanol as extractant. To investigate the extraction time on cosmetics and safrole, a methyl 6 influence extraction efficiency. In the blank sample by adding the same amount of safrole and 6-methyl coumarin, were extracted 10,20,30,40 min,[link widoczny dla zalogowanych], determination of recovery. Safrole recoveries were 89%, 91%, 99%, 92%; 6, a methyl recoveries were 93%, 96%, 103%,[link widoczny dla zalogowanych], 99%, the recovery can be seen from the measurement the efficiency of extraction of 10-40min was no significant difference. As a result of ultrasound time, the water temperature gradually increased, and the more volatile substances measured, vulnerable to heat loss, but not completely dissolve the sample ultrasonic 10min, so I chose ultrasound time was 20min. 2.2 Optimization of chromatographic conditions for the physical properties of objects under test,[link widoczny dla zalogowanych], using a HP 5MS capillary column. Initial column temperature was low, the peak time is too long, so the starting temperature of 90; to 10 ~ Jmin warming, both substances (10) peak well (Figure 1). 4. Called b. H. Time Period t/rain1 HJl000l2H a safrole; 2-6 Figure 1-methyl coumarin and safrole, a methyl 6 total ion mass spectrometry conditions of Figure 2.3 to determine the actual test samples, if the sample The peak is very close to the standard peak, the retention time is difficult to rely only on qualitative, so the use of mass spectrometry samples were confirmed,[link widoczny dla zalogowanych], with the standard spectral library comparison of mass spectra to rule out the possibility of erroneous results. This method uses full scan, mass range of 45 ~ 250amu; solvent delay 3min. Characteristics of safrole ions (relative abundance ratio): 162amu (100%), 131amu (34.7%), 104amu (38.9%); 6-methyl coumarin characteristic ions (relative abundance ratio): 160anlu ( 1OO%), 132amu (74.3%), 131ainu (50.9). 2.4 The linear relationship as determined by the experimental conditions, take a series of standard solution (n = 7) were measured. The results showed that safrole concentration () in the 0.5-100 ~ g / ml range and the peak area (Y) is linear, the linear equation y = 2.15445359x +1.10724, r = 0.9988 . The peak area (y) the corresponding concentration of 6-methyl coumarin () mapping (n: 6), show that 6-methyl coumarin concentration range of 1 ~ 100ml linear relationship between the linear equation y = 2.47998542x +0.31242, r = 0.9999. 2.5 Methods of measurement limit of blank sample in a number of 1.000g were added to different concentrations of safrole and 6-methyl coumarin mixed standard solution, after treatment in accordance with Section 1.3.1, using gas chromatography samples were determined, in accordance with Section 2.4 Calculation of linear equations. The S / N = 10 calculated sassafras cable, 6-methyl coumarin determination of a limit, respectively, 5,10 g / g. Experiments showed that when less than the concentration of added time, the peak noise and blank samples is very difficult to distinguish. 2.6 The recovery and precision of the non-selected one of safrole and 6-methyl cosmetics, set for each substance concentration of 3, determined by method of experimental conditions, each concentration for 6 experiments, the measured results in Table 1. Table 1 safrole and 6-methyl coumarin recovery results (n = 6) 2.7 Detection of the actual samples detected by this method cosmetic samples, were not detected safrole and 6. Methylcoumarin. The method showed good accuracy and sensitivity, small amount of sample,[link widoczny dla zalogowanych], detection period is short, with satisfactory results.
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