Assessment of Silicone Polymer Composites for Environmental Forensic Applications: A Proof of Concept Study*

Abstract: This study evaluates the use of polydimethylsiloxane polymer composites (PDMS, Fe–PDMS) as a passive sampling media to preconcentrate analytes found in environmental settings. Samplers were made using commercially available silicone products. The composite samplers were assessed for their sorption properties using Atrazine and Irgarol 1051 as model compounds. The initial study assessed the utility of PDMS sheets as adsorption material by following analyte depletion from spiked water samples by solid‐phase microextraction gas chromatography/mass spectrometry (GC/MS). Follow‐up studies conducted at high and low concentrations using lab manufactured iron‐ PDMS rods (Fe–PDMS) showed effective uptake at differential rates from concentrations ranging between 1 μg/L and 10 μg/L. Adsorption mechanism was reversible, and compounds were recovered from the exposed materials and analyzed by liquid–liquid extraction‐GC/MS. Both composites showed better affinity for Irgarol 1051, 100% removal, than for Atrazine, 30% removal, likely representing their K_OW differences, 3.6 and 2.6, respectively. This “proof of concept” study demonstrates the positive implications for the use of silicon polymer composites as a monitoring tool for environmental forensic purposes.     

Synthetic Performance Indicators for Residential Housing Agencies

Many public administrations produce and distribute public services through a number of similar local autonomous organizations, or institutions, operating in different parts of the territory assigned to them under a centralized authority. Examples of this are the public residential housing institutions, the institutions for waste disposal, health care institutions, and education institutions. The problem arises regarding the evaluation of the performance of these local organizations and institutions not in absolute but in relative terms, in order to determine what incentives or sanctions should be meted out to them. This study presents the methodological problems, the data analysis, and the initial results of the method adopted by the Lombardy Region to create a system of performance indicators that will permit an automatic ranking of the Residential Housing Agencies in Lombardy （ALER） according to their performance, based on information from their balance sheets. A performance index was devised by rationally combining the results of three different analyses： position analysis, ranking analysis, and scoring analysis. The results allowed the central administration to： （1） motivate the managers of the local units through a system of performance-based incentives; （2） aggregate poorly performing local units or outsource inefficient functions; and （3） create competition among local units and raise overall performance levels.     

Homicide by unusual‐edged weapons: Forensic considerations of two cases

Homicide by stab wound is common worldwide. However, the use of unusual edged weapons is rarely reported in the forensic literature. Here, we report two cases of homicide involving a Japanese sword, or katana, and a sickle. Both of these weapons can create either stab or incised wounds with some particularities. In our cases, characteristics of the external wounds, internal injuries, and the depth of penetration raised the possibility of an unusual weapon. Meticulous forensic examination of these injuries (morphological characteristics, depth of penetration, trajectories, and cut marks in the bone) may allow the forensic expert to determine the type of weapon used.     

Identification of furosemide in hair in a post‐mortem case by UHPLC‐MS/MS with guidance on interpretation

Testing for drugs in hair raises several difficulties. Among them is the interpretation of the final concentration(s). In a post‐mortem case, analyses revealed the presence of furosemide (12 ng/mL) in femoral blood, although it was not part of the victim's treatment. The prosecutor requested our laboratory to undertake an additional analysis in hair to obtain information about the use of furosemide. A specific method was therefore developed and validated to identify and quantify furosemide in hair by UHPLC‐MS/MS. After decontamination of 30 mg of hair, incubation in acidic condition, extraction with ethyl acetate, the samples were analyzed by UHPLC‐MS/MS. Furosemide was found in the victim's hair at 225 pg/mg. However, it was not possible to interpret this concentration due to the absence of data in the literature. Therefore, the authors performed a controlled study in two parts. In order to establish the basis of interpretation, several volunteers were tested (four after a single 20 mg administration and twenty‐four under daily treatment). The first part indicated that a single dose is not detectable in hair using our method. The second part demonstrated concentrations ranging from 5 to 1110 pg/mg with no correlation between dosage and hair concentrations. The decedent's hair result was interpreted as repeated exposures. In the case of furosemide analysis, hair can provide information about its presence but cannot give information about dosage or frequency of use.