Comparison of DAD and FLD Detection for Identification of Selected Bisphenols in Human Breast Milk Samples and Their Quantitative Analysis by LC-MS/MS.

BACKGROUND

Determination of bisphenols released from packaging material is undoubtedly a difficult and tricky task, requiring the chemical analyst to develop an individual approach to obtain reliable analytical information.

OBJECTIVE

QuECHERS (Quick, Easy, Cheap, Effective, Rugged, and Safe)/dispersive solid-phase extraction (d-SPE) technique and high performance liquid chromatography (HPLC) coupled with modern detection techniques such as diode-array detector (DAD), fluorescence detector (FLD) or tandem mass spectrometry (MS/MS) for the determination of bisphenols such as bisphenol A (BPA), bisphenol S (BPS), bisphenol F (BPF), bisphenol B (BPB), 2-[[4-[2-[4-(Oxiran-2-ylmethoxy)phenyl]propan-2yl]phenoxy] methyl]oxirane (BADGE), 3-[4-[2-[4-(Oxiran-2-ylmethoxy)phenyl]propan-2-yl]phenoxy]propane-1,2-diol (BADGEH2O), 3-[4-[2-[4-(2,3-Dihydroxypropoxy)phenyl]propan-2-yl]phenoxy]propane-1,2-diol (BADGE2H2O), 1-Chloro-3-[4-[2-[4-(3-chloro-2-hydroxypropoxy)phenyl] propan-2-yl]phenoxy]propan-2-ol (BADGE*2HCl) in human breast milk samples have been performed.

METHODS

For the analysis of total analytes, prior to the extraction with acetonitrile, a deconjugation step was implemented in a tube by adding 1 mL of the enzymatic solution with the β-Glucuronidase to 5 mL of sample. The mix was homogenized and incubated for 17 h at 37°C. Ten milliliters of acetonitrile, and a QuEChERS salt packet with 4 g anhydrous MgSO4 and 1 g NaCl were added. During the d-SPE step the extract was transferred into tube with 30 mg Z-Sep and 50 mg PSA (and also 150 mg MgSO4 for LC-MS/MS analysis). MeOH-water (20:80, v/v) were added to the dry residue and the extract was reconstituted in 150 µL (25-fold analytes pre-concentration is achieved). Next bisphenols were identified by HPLC-DAD-FLD and quantified by LC-MS/MS equipment.

CONCLUSIONS

During the bisphenols HPLC-DAD-FLD analysis, from 6 min a reinforcement of 15 was used, which allowed analytes to be identified at 750 pg/mL. Application of LC-MS/MS allowed quantification of bisphenols in the range from 2.12 to 116.22 ng/mL in a total 27 human breast milk samples.

HIGHLIGHTS

First QuEChERS/d-SPE coupled with HPLC-DAD-FLD or LC-MS/MS method for the quantification of bisphenols and its analogues in breast milk Faster and cheaper alternative to traditional extraction methods The method was applied for the first biomonitoring of bisphenols and its analogues in breast milk.