Occurrence of chloramphenicol in cereal straw in north-western Europe

Figures & data

Figure 1. ELISA data plotted against LC-MS/MS data with linear regression statistics.

Figure 2. (colour online) Box–Whisker plot of the results of analysis of CAP by LC-MS/MS (LOQ = 0.1, LOD = 0.05) and ELISA (minimum observed level = 0.6) respectively. All values are in µg kg^–1. Boxes represent second and third quartiles with median (horizontal line) and mean (×) indicated.

Figure 3. Geographical distribution of samples with indication of CAP content. Open circles: < 1 µg kg^–1; grey circles 1–10 µg kg^–1; black circles > 10 µg kg^–1.

Table 1. Summary of results of content of chloramphenicol in straw sampled in Northwest Europe grouped per country of origin.

Country	Number of samples	Number of CAP containing samples (> 0.1 µg kg^−1)	Highest content of CAP (µg kg^–1)	Average content of CAP (µg kg^–1)	Median content (µg kg^–1)
The Netherlands	75	25	6.3	0.7	0.3
Germany	13	4	4	0.4	0.2
France	14	4	0.2	0.2	0.2
UK	2	2	0.2	0.2	0.2
Denmark	1	1	1	< 0.1	< 0.1

Table 2. Summary of results of analyses of chloramphenicol in cereal straw sampled at Swedish farms.

Species	Number of samples	Number of samples with CAP > 1 µg kg^–1	Highest content of CAP (µg kg^–1)	Average content of CAP (µg kg^–1)	Median content (µg kg^–1)
Barley	106	30	21.5 (31.7^a)	1.5	< 1
Wheat	46	12	10.7 (18.0^a)	1.1	< 1
Oats	29	2	4.1 (0^a)	< 1	< 1
Triticale	8	1	1.3 (–)	< 1	< 1
Unspecified bedding straw	20	9	3.2 (2.4^a)	1.1	< 1

Note: ^aFigures in parentheses represent confirmed contents quantified by LC-MS/MS.

Table 3. Regional distribution in Sweden of straw samples containing more than 1 µg/kg CAP.

County where CAP was detected	Number of samples	Number of Samples with CAP > 1 µg kg^–1	Highest content of CAP (µg kg^–1)
Skåne	50	32	20
Gotland	3	3	32
Västra Götaland	24	4	2
Uppland	16	2	2^a
Hälsingland	7	1	4^a
Östergötland	16	3	3
Halland	11	1	2^a
Västerbotten	7	1	2^a
Södermanland	13	1	1^a
Värmland	12	2	1^a
Blekinge	10	2	1^a
Kalmar	8	1	1^a
Dalarna	11	1	1^a

Note: ^aNot positively identified and quantified by LC-MS/MS.