Title : 
 Mercury and explosive compound 4 - aminodinitrotoluene ( 4 - ADNT ) in dab ( Limanda limanda ) caught at munition dumping site Kolberger Heide in the Kiel Bight , Baltic Sea 

 Abstract : 
 Dumped munitions contain various harmful substances which can affect marine biota like fish . One of them is mercury ( Hg ) , included in the common explosive primer . Another is 4 - aminodinitrotoluene ( 4 - ADNT ) , an explosive - metabolite . 251 individual dab ( Limanda limanda L. ) caught at the dump site Kolberger Heide a and nearby reference sites in 2017 and 2018 were analysed . The table contain individual data on Hg , 4 - aminodinitrotoluene , age , length , weight , sex and condition factor . Mercury at AAS For sample preparation , portions of muscle samples were freeze dried using a lyophilizer and subsequently homogenized using an agate mortar or an ultra turrax tube drive dispenser ( IKA , Staufen , Germany ) equipped with glass grinders respectively to obtain a dry sample powder suitable for Hg analysis . Total Hg was determined by atomic absorption spectrometry using a Direct Mercury Analyzer ( DMA-80 , MLS , Leutkirchen , Germany ) . Known amounts ( 20–30 mg ) of each sample were weighted into the boat containers ( precleaned with nitric acid ) of the DMA-80 . Direct analysis for total Hg content was performed using a 10 - level calibration with standards in 0.5 M nitric acid . The accuracy of the procedure was determined by analysis of Certified Reference Material ( DORM-3 and DORM-4 , both fish protein homogenates ) obtained from the National Research Council ( NCR ) in Canada which was taken through the same analytical procedure as the samples . Details on reference materials are given in Table 1 . All samples were analysed in triplicate . External quality assurance was done by successfully participation in laboratory proficiency tests ( z - score 0.7 ) conducted by QUASIMEME ( www.wepal.nl ) designed for marine environment analytics . The limit of detection ( LD ) and the limit of quantification ( LQ ) were calculated from a standard curve according to DIN 32,645 ( DIN , 1994 ) with a confidence level of 99 % . Considering the sample preparation , a LD of 0.080 µg / kg wet weight ( w. w. ) and a LQ of 0.230 µg / kg w. w. were determined for Hg . No values below these limits were found in any sample under investigation . Recovery of the method was 100.3 % and precision was 8.20 % . Explosives at LC - MS / MS 5 μL of the final bile extract were injected on a column in an Agilent 1290 Infinity High - Performance - Liquid - Chromatograph coupled to an AB Sciex QTrap 5500 Triple Quadrupole / Ion - Trap Mass Spectrometer ( HPLC - MS ) . Gradient separation was achieved using an Acclaim Explosives E2 Column ( Thermo Fisher Scientific ) kept at 22 ° C . Ionization was conducted in negative atmospheric pressure chemical ionization ( APCI ) mode . Explosives and selected metabolites were detected via a multiple reaction monitoring ( MRM ) mode based on characteristic MS / MS transitions , previously optimized using commercially available standard substances . Characterisation of unknown compounds was achieved in scan - mode of the linear ion trap by selecting nitroaromatic compounds using a neutral loss scan targeting the loss of nitro - groups ( m / z 46 ) , followed by an enhanced product ion scan , producing a sensitive mass spectrum of the nitro - containing molecule . Abundances of explosive compounds were quantified via the internal standard 1,4 - DNB and corrected for response factors . Response factors were determined using an external calibration covering the expected range of concentrations . The method used is described in detail by Koske et al . ( 2019 ) . Limits of detection ( LOD ) and limits of quantitation ( LOQ ) for explosive compounds were calculated according to DIN 32645 ( 2008 ) . LOD 4 - ADNT : 2.8 ng / ml bile . LOQ 4 - ADNT : 18.8 ng / ml bile .