When Good Intentions Go Bad-False Positive Microplastic Detection Caused by Disposable Gloves.

Apart from being considered a potential threat to ecosystems and human health, the ubiquity of microplastics presents analytical challenges. There is a high risk of sample contamination during sampling, sample preparation, and analysis. In this study, the potential of sample contamination or misinterpretation due to substances associated with disposable laboratory gloves or reagents used during sample preparation was investigated. Leachates of 10 different types of disposable gloves were analyzed using Raman microspectroscopy (µ-Raman), Fourier-transform infrared microspectroscopy (µ-FTIR), and pyrolysis-gas chromatography/mass spectrometry (pyr-GC/MS). There appeared to be polyethylene (PE) in almost all investigated glove leachates and with all applied methods. Closer investigations revealed that the leachates contained long-chain compounds such as stearates or fatty acids, which were falsely identified as PE by the applied analytical methods. Sodium dodecyl sulfate, which is commonly applied in microplastic research during sample preparation, may also be mistaken for PE. Therefore, µ-Raman, µ-FTIR, and pyr-GC/MS were further tested for their capability to distinguish among PE, sodium dodecyl sulfate, and stearates. It became clear that stearates and sodium dodecyl sulfates can cause substantial overestimation of PE.

Evaluation of the immunogenicity and reactogenicity of a DTPa-HBV-IPV Combination vaccine co-administered with a Hib conjugate vaccine either as a single injection of a hexavalent combination or as two separate injections at 3, 5 and 11 months of age.

A combined DTPa-HBV-IPV/Hib vaccine containing diphtheria (D), tetanus (T), acellular pertussis (Pa), hepatitis B (HBV) and types 1, 2 and 3 inactivated polioviruses (IPV) extemporaneously mixed with a conjugated Haemophilus influenzae type b (Hib) vaccine (Group 1) was compared to the DTPa-HBV-IPV and Hib vaccines (Group 2) administered separately at 3, 5 and 11 months of age (n = 440). A microneutralization assay was used to detect antibodies against the 3 polio virus types (cut-off 1:8 dil), RIA for anti-HBs antibodies (cut-off 10 mIU/ml) and ELISA for antibodies against all other vaccine antigens (cut-off: 0.1 IU/ml for anti-tetanus and anti-diphtheria antibodies; 5 El.U/ml for antibodies against each of the 3 acellular pertussis antigens and 0.15 microg/ml for anti-PRP antibodies). Similar immune responses were observed in both groups 1 month after dose 2 as well as after dose 3. Six months after dose 2 however, the proportion of subjects maintaining an anti-tetanus antibody concentration > or = 0.1 IU/ml was lower in Group 2 and a slight group difference in favour of Group 1 was also observed for anti-PRP, anti-diphtheria and anti-polio type 1 antibody persistence prior to the third dose. The overall incidence of local and general solicited symptoms was similar in both groups. One subject discontinued study vaccination following an SAE considered to be related to vaccination. The DTPa-HBV-IPV/Hib combined vaccine is immunogenic and well tolerated when administered according to a 3, 5 and 11 month vaccination schedule and can therefore be considered as a feasible alternative to the separate administration of the pentavalent DTPa-HBV-IPV and the monovalent Hib vaccines.