Concentrations of antimicrobials in soil batch tests

Component(s)aConcn (ng/ml or ng/g [dry wt]) of b:
Individual componentsc
    Farm LF manured4.4 (1.4)19.8 (1.4)5.3 (1.5)2,630.0 (836.0)≤6.0<51,230.5 (15.5)
    Farm OF2 manured<260.1 (6.0)723.9 (100.9)126.5 (12.5)20.9 (14.9)≤445.8 (2.8)
    Soil<2<1<18.1 (3.4)≤3.8≤4.9≤6.5
Batch tests
    1× farm LF manureNA/NAe1.1/<10.3/7.1159.9/21.34.9/5.95.8/<278.2/11.5
    4× farm LF manureNA/NA4.7/<11.3/<1631.4/171.76.1/<25.9/<2298.9/69.9
    1× farm OF2 manureNA/NA3.4/<140.7/8.215.8/<15.6/<25.9/<29.9/<2
    4× farm OF2 manureNA/NA13.2/<1159.1/26.736.3/1.78.9/<26.8/<217.2/4.9
    1× farm OF2 manure + 1× chlortetracyclineNA/NA3.4/7.6602.8/41.516.0/12.65.7/20.76.0/1110.0/18.1
    1× farm OF2 manure + 4× chlortetracyclineNA/NA3.7/6.42,444.1/166.917.1/1.66.1/10.36.4/<210.7/5.1
    1× farm OF2 manure + 1× lincomycin1,130.8/311.6NA/NANA/NANA/NANA/NANA/NANA/NA
    1× farm OF2 manure + 4× lincomycin4,492.3/1,560.7NA/NANA/NANA/NANA/NANA/NANA/NA
  • a For 1× amendments 8 g manure was added to 200 g soil.

  • b The concentrations in manure are expressed in ng/ml, and the concentrations in soil and amended soil are expressed in ng/g (dry weight). Erythromycin, spiramycin, oleandomycin, tiamulin, tilmicosin, and tylosin A concentrations were analyzed for the same samples as lincomycin concentrations and were always below the detection limit. The values in parentheses for individual components are the half-ranges for duplicate measurements. Measurements below the detection limit for individual components were handled as described in Table 1, footnote a. The values for the batch tests are initial concentrations (estimated using data for individual components)/final concentrations (measured after 90 days of incubation). For estimation of the initial concentrations values below the detection limit were assumed to be zero.

  • c Individual components were sampled for analysis on day 0.

  • d Antimicrobial concentrations in farm LF and OF2 manure were reported previously (31) and are included for comparison.

  • e NA, not analyzed or calculated.