Development and implementation of an analytical procedure for the quantification of natural and synthetic steroid hormones in whole surface waters.

Natural and synthetic steroid hormones are chronically released into aquatic spheres. Whereas knowledge on their combined mode of action and the cocktail effect are needed, only few multi-class methods address the challenge of their trace quantification in surface waters. The current study describes a sensitive multi-residue analytical strategy aiming to quantify 23 steroid hormones belonging to androgens, estrogens, glucocorticoids and progestogens in whole surface waters.

Road impact in a protected area with rich biodiversity: the case of the Sebitoli road in Kibale National Park, Uganda.

While road network expansion is crucial for economic development, it can cause a notable disturbance of fauna, especially in protected area in terms of habitat fragmentation, risk of collision, and also indirect threat such as pollution. In this study, we monitored the 4.6-km long tarmac road crossing the Kibale National Park in Uganda, home to a rich variety of wild species including the endangered chimpanzees.

Composition and endocrine effects of water collected in the Kibale national park in Uganda.

Pesticides are used worldwide with potential harmful effects on both fauna and flora. The Kibale National Park in Uganda, a site renowned for its biodiversity is surrounded by tea, banana and eucalyptus plantations as well as maize fields and small farms. We previously showed presence of pesticides with potential endocrine disruptive effects in the vicinity.

Validation of a method to monitor the occurrence of 20 relevant pharmaceuticals and personal care products in 167 bottled waters.

Research on emerging substances in drinking water presents major interest and the possibility of trace contamination has seen increasing concern from the scientific community and the public authorities. More particularly, residues of pharmaceuticals and personal care products (PPCPs) in bottled water are a very important issue due to societal concerns and potential media impact. In this context, it has become necessary to carry out reliable monitoring.

Development of a multi-residue method for scrutinizing psychotropic compounds in natural waters.

The present work describes a multi-residue SPE-UPLC-MS/MS method aiming at the characterization of 68 compounds in natural waters, including parent compounds as well as their major metabolites and glucuronide conjugates. Development was conducted toward the quantitative determination of a broad range of analytes belonging to different class of psychotropic drugs such as benzodiazepines, antidepressants, stimulants, opiates and opioids, anticonvulsants, anti-dementia drugs, analgesic and anti-inflammatory drugs (as anthropic indicators) in the low ngL range of concentration. Satisfactory extraction recoveries >70% were obtained for the majority of analytes (49 out of 68) allowing low limits of quantification.

Validation and uncertainties evaluation of an isotope dilution-SPE-LC-MS/MS for the quantification of drug residues in surface waters.

The present work describes the development and validation of a reference method conducted at the French National Institute of Metrology (LNE) for the quantitative determination of psychoactive compounds in the dissolved fraction of surface waters. More specifically an isotope dilution-SPE-LC-MS/MS based method has been implemented for the characterization of a broad range of analytes belonging to different classes of psychotropic drugs such as benzodiazepines, antidepressants, stimulants, opiates and opioids, anticonvulsants, anti-dementia drugs, analgesics as well as the anti-inflammatory drug diclofenac in the low ng L(-1) range of concentration. Full validation of the method was performed following procedures described by the French standard NF T90-210.

Performance of high-resolution SEM/EDX systems equipped with transmission mode (TSEM) for imaging and measurement of size and size distribution of spherical nanoparticles.

The analytical performance of high-resolution scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDX) for accurate determination of the size, size distribution, qualitative elemental analysis of nanoparticles (NPs) was systematically investigated. It is demonstrated how powerful high-resolution SEM is by using both mono- and bi-modal distributions of SiO2 airborne NPs collected on appropriate substrates after their generation from colloidal suspension. The transmission mode of the SEM (TSEM) is systematically employed for NPs prepared on thin film substrates such as transmission electron microscopy grids.

Method development for genomic Legionella pneumophila DNA quantification by inductively coupled plasma mass spectrometry.

The development of a method for the quantification of Legionella pneumophila genomic deoxyribonucleic acid is considered. The method is based on the quantification by inductively coupled plasma mass spectrometry (ICP-MS) of the mass fraction of phosphorus, stoichiometrically presented in the DNA molecules. Through the DNA sequencing data, it was possible to convert the ICP-MS analysis results into DNA genome units.

Validation of a reference method for total cholesterol measurement in human serum and assignation of reference values to proficiency testing samples.

Objectives: Our objective was to develop a reference method to measure total cholesterol in human serum, in order to assign values and assess the accuracy of field methods in French clinical laboratories.

Design And Methods: A reference method based on gas chromatography coupled with mass spectrometry and isotope dilution (GC-IDMS) was developed and validated. It was then used to assign reference values to five frozen serum samples from voluntary proficiency testing schemes gathering 170 French clinical laboratories.

Continuous improvement of medical test reliability using reference methods and matrix-corrected target values in proficiency testing schemes: application to glucose assay.

The reliability of biological tests is a major issue for patient care in terms of public health that involves high economic stakes. Reference methods, as well as regular external quality assessment schemes (EQAS), are needed to monitor the analytical performance of field methods. However, control material commutability is a major concern to assess method accuracy.

A new certified reference material for benzene measurement in air on a sorbent tube: development and proficiency testing.

A certified matrix reference material (CRM) for the measurement of benzene in ambient air has been developed at Laboratoire National de Métrologie et d'Essais. The production of these CRMs was conducted using a gravimetric method fully traceable to the International System of Units. The CRMs were prepared by sampling an accurate mass of a gaseous primary reference material of benzene, using a high-precision laminar flowmeter and a mass flow controller, with a PerkinElmer sampler filled with Carbopack™ X sorbent.

A systematic approach to the accurate quantification of selenium in serum selenoalbumin by HPLC-ICP-MS.

In this paper, two different methods are for the first time systematically compared for the determination of selenium in human serum selenoalbumin (SeAlb). Firstly, SeAlb was enzymatically hydrolyzed and the resulting selenomethionine (SeMet) was quantified using species-specific isotope dilution (SSID) with reversed phase-HPLC (RP-HPLC) hyphenated to (collision/reaction cell) inductively coupled plasma-quadrupole mass spectrometry (CRC ICP-QMS). In order to assess the enzymatic hydrolysis yield, SeAlb was determined as an intact protein by affinity-HPLC (AF-HPLC) coupled to CRC ICP-QMS.