Monitoring of Polycyclic Aromatic Hydrocarbons (PAH) in food ...

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
peer-00704676, version 1 - 6 Jun 2012
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
by means of a 0.45 µm syringe filter and injected on a DACC column (Chromspher Pi, 80 x 0,3 mm) using 2-
propanol as mobile phase. After removal of matrix components using 2-propanol as the eluent, the PAH were
stripped from the DACC column by means of ethylacetate – acetonitril (70/30 v/v) and subjected to 2 reversed
phase analytical columns in series (Lichrocart 250-4 Lichrospher PAH RP-18 5 µ m) prior to quantification of the
PAH by variable wavelength fluorescence detection.
Cyclopenta[cd]pyrene and benzo[j]fluoranthene were not included in the method because of low
For Peer Review Only
fluorescence intensities. Moreover, indeno[1,2,3-cd]pyrene could also not be included. The analysis of
indeno[1,2,3-cd]pyrene would require different wavelength settings, but these could not be implemented because
of insufficient resolution of this PAH and dibenzo[a,e]pyrene. Use of a multi-channel fluorescence detector
combined with a photo diode array detector would have allowed for the determination of these remaining three
PAH, but our routine method was not equipped with these features at that time. The main alterations to the
method already described by van der Wielen et al. ( 2006) were in the mobile phase gradient and the
fluorescence wavelength settings and these are presented in Tables 2 and 3, respectively. The method of
analysis was in-house validated according to ISO 17025 guidelines. The limit of detection (LOD) was determined
based on the signal to noise ratio. The LOD was defined as the concentration at which the peak height
corresponds with 3 times the bandwidth of the noise; the limit of quantification (LOQ) was defined as 6 times the
bandwidth of the noise. During the validation study, performance criteria such as precision under repeatability and
reproducibility conditions, trueness, recovery and measurement uncertainty were established (Table 4). During
the analyses, measurement quality was assured by means of random analysis of standard control samples of
food supplements, which were monitored in time by Shewhart control charts (Thompson and Wood 2005).
Intake estimates and statistics
Food Additives and Contaminants
Intakes of benzo[a]pyrene, PAH2, PAH4 and PAH8 with a supplement when used at the maximum dose level
were estimated for several supplements in which relatively high concentrations of benzo[a]pyrene were found.
The daily intake of these PAH with a supplement was calculated from the weight of one unit (determined by
preferably weighing 10 or more units), the analytically determined PAH level and the maximum recommended
daily use level stated on the label. When a supplement consisted of capsules or soft gels, only PAH levels of its
http://mc.manuscriptcentral.com/tfac Email: fac@tandf.co.uk
8
Page 8 of 40