What’s New in Chromatography?

Probing problematic pesticides. Broad-spectrum insecticides – called neonicotinoids (NEOs) – are rapidly replacing traditional organophosphorus and organochlorine-based insecticides. Some studies have already reported adverse effects of NEOs on mammalian health – but the relationship between NEO exposure and toxic effects on the human liver remains unclear. And that’s why researchers have recently attempted to examine the link by quantifying eight commercialized NEOs in human bile using ultra-performance liquid chromatography combined with triple quadrupole mass spectrometry. The results indicate that neonicotinoids – particularly dinotefuran and nitenpyram – were not completely degraded in the liver and were found at high frequencies and concentrations in bile. According to the press release, these neonicotinoids are “likely to be reabsorbed by the intestine and enter the circulatory system, eventually accumulating in the liver and causing hepatotoxicity and enterohepatic circulation disruption.”

Sweat it out. Cystic fibrosis is caused by a defective cystic fibrosis transmembrane conductance regulator (CFTR) gene. The absence of the CFTR protein in patient sweat glands leads to a notable side effect known as aquagenic palmoplantar keratoderma (AKP), which spurred researchers to analyze sweat from CF patients. Using LC-MS/MS, they discovered that 57 proteins were differentially expressed between the patients and controls. The CF sweat proteome was characterized by 25 upregulated and 32 downregulated proteins. According to the authors, the sweat proteome could eventually be used as the basis of a diagnostic tool for CF and potentially reveal treatment options for AKP.

Bare bones. The bone proteome (or osteo-ome, if you prefer) is a rich source of information for forensic studies. But forensic biomarkers based on the bone proteome are typically assessed using skeletal remains from human taphonomy facilities (body farms – yes, they exist), which use accelerated methods to clean the bones. UK-based researchers decided to investigate one such technique called maceration, which uses water and heat to de-flesh the bones. On comparing the proteomes (determined by LC-MS/MS) of untreated and macerated (three different protocols) bovine bones, the researchers revealed clear distinctions between proteomes, as well as lower protein abundances with increasing maceration time. The authors recommended the introduction of a standardized method to minimize protein degradation – and to avoid maceration completely where possible.