Determination of 9, 10-phenanthrenequinone in airborne particulates by High-Performance Liquid Chromatography with post-column fluorescence derivatization using 2-aminothiophenol

Rapid analysis of quinones in complex matrices by derivatization-based wooden-tip electrospray ionization mass spectrometry

Quinones are important components participating in various biological processes as well as hazardous substances to human health. Rapid determination of quinones in environmental samples and biofluids is the basis for assessing their health effect. Here, we presented a rapid, straightforward, highly sensitive and environmental-friendly wooden-tip electrospray ionization mass spectrometry (ESI-MS) method for the determination of quinones in PM2.5, urine and serum. An amine group "tag" was introduced to the quinone structure through in situ derivatization with cysteamine to improve ionization efficiency of quinones in wooden-tip ESI-MS. The toothpicks were treated by sharpening and acidification with HNO₃. Experimental parameters, including sample volume, spray voltage, and spray solvent composition were optimized to be 1 μL, 3.5 kV, and ACN/CH₃COOC₂H₅ (v/v, 9:1), respectively. The limits of detection for the determination of 1,4-benzoquinone, methyl-p-benzoquinone, 1,4-naphthoquinone and 1,4-anthraquinone in ACN under the optimal conditions were 1.00, 0.96, 0.13, 0.16 ng (1.00, 0.96, 0.13, 0.16 μg/mL, sample volume, 1 μL), respectively. This approach was successfully applied to the determination of 1,4-naphthoquinone and 1,4-anthraquinone in complex matrices, including PM2.5, urine and serum without or with minimal sample preparation (LOD range: 0.22-1.48 ng).

Cytotoxicity of Air Pollutant 9,10-Phenanthrenequinone: Role of Reactive Oxygen Species and Redox Signaling

Atmospheric pollution has been a principal topic recently in the scientific and political community due to its role and impact on human and ecological health. 9,10-phenanthrenequinone (9,10-PQ) is a quinone molecule found in air pollution abundantly in the diesel exhaust particles (DEP). This compound has studied extensively and has been shown to develop cytotoxic effects both in vitro and in vivo. 9, 10-PQ has been proposed to play a critical role in the development of cytotoxicity via generation of reactive oxygen species (ROS) through redox cycling. This compound also reduces expression of glutathione (GSH), which is critical in Phase II detoxification reactions. Understanding the underlying cellular mechanisms involved in cytotoxicity can allow for the development of therapeutics designed to target specific molecules significantly involved in the 9,10-PQ-induced ROS toxicity. This review highlights the developments in the understanding of the cytotoxic effects of 9, 10-PQ with special emphasis on the possible mechanisms involved.

An environmental pollutant, 9,10-phenanthrenequinone, activates human TRPA1 via critical cysteines 621 and 665

Transient receptor potential ankyrin 1 (TRPA1) is activated by noxious cold, mechanical stimulation, and irritant chemicals. In our recent study, 9, 10‐phenanthrenequinone (9,10‐PQ) is the most potent irritant for activation of NRF2 among 1395 cigarette smoke components and it may be, therefore, important to find its additional targets. Here, we show that 9,10‐PQ functions as an activator of TRPA1 in human embryonic kidney (HEK) cells expressing human wild‐type TRPA1 (HEK‐wTRPA1) and human alveolar A549 (A549) cells. Application of 9,10‐PQ at 0.1–10 μmol/L induced a concentration‐dependent Ca²⁺ response as well as inward currents at −50 mV in HEK‐wTRPA1 cells. The current response was blocked by TRPA1 antagonists, HC‐030031 (HC) and A‐967079. To test whether 9,10‐PQ affects the cysteine residues of TRPA1, we expressed mutant TRPA1 channels in HEK cells (HEK‐muTRPA1) in which six different cysteine residues were replaced with serine. Among them, a mutation of cysteine 621 (C621S) abolished the 9,10‐PQ‐induced Ca²⁺ and current responses. The channel activity induced by 9,10‐PQ was also abolished in excised inside‐out patches isolated from HEK‐muTRPA1 cells with the C621S substitution. Although a mutation of cysteine 665 (C665S) reduced the 9,10‐PQ‐induced response, channel sensitization by pretreatment with Cu²⁺ plus 1,10‐phenanthroline and by internal dialysis of 3 μmol/L Ca²⁺ restored the response. However, a double mutant with C621S and C665S substitutions had little response to 9,10‐PQ, even when sensitized by Ca²⁺ dialysis. In A549 cells, 9,10‐PQ induced an HC‐sensitive Ca²⁺ response. Our findings demonstrate that 9,10‐PQ activation of human TRA1 is dependent on cysteine residues 621 and 665.

Reactive paper spray mass spectrometry for in situ identification of quinones

RATIONALE

The polycyclic aromatic hydrocarbons quinones are reported to be harmful and could cause mutations and cancer via the generation of reactive oxygen species through their redox cycle in human body. For detection by gas chromatography and high-performance liquid chromatography mass spectrometry (MS), sample pretreatments and chromatographic separation prior to MS are generally required, which makes the whole analytical process laborious and time-consuming, resulting in difficulties for fast screening targets from complicated matrices. Thus facile, rapid and reliable MS methods for detection of quinones in complicated matrices are in great demand.

METHODS

Reactive paper spray mass spectrometry is reported for rapid identification and quantification of quinones in complicated matrices. The method is based on an in situ derivatization reaction between cysteamine and quinones prior to analysis with paper spray mass spectrometry. With the addition of an easily charged chemical tag, the ionization efficiency of analysts is greatly improved. Due to the high ionization efficiency of the drivatives, quinones in complicated matrices could be detected rapidly without any pretreatment.

RESULTS

Under the optimized experimental conditions, the linear dynamic ranges for both 1,4-benzoquinone and 1,4-naphthoquinone are 0.4-40 ng and that for 1,4-anthraquinone is 0.4-20 ng. Limits of detection for these three analytes were measured to be 160, 40 and 200 pg using methyl-p-benzoquinone as internal standard. The capability to conduct MS analysis under ambient pressure is illustrated by identification of 1,4-naphthoquinone and 1,4-anthraquinone in raw urine, raw serum and cell culture medium.

CONCLUSIONS

Reactive paper spray could be applied to fast screening of quinones from complicated matrices. Therefore, we believe that reactive paper spray mass spectrometry might be potentially useful in the fields of environmental sciences, metabolomics and clinic analysis.

[Development of selective determination methods for quinones with fluorescence and chemiluminescence detection and their application to environmental and biological samples]

Quinones are compounds that have various characteristics such as a biological electron transporter, an industrial product and a harmful environmental pollutant. Therefore, an effective determination method for quinones is required in many fields. This review describes the development of sensitive and selective determination methods for quinones based on some detection principles and their application to analyses in environmental, pharmaceutical and biological samples. Firstly, a fluorescence method was developed based on fluorogenic derivatization of quinones and applied to environmental analysis. Secondly, a luminol chemiluminescence method was developed based on generation of reactive oxygen species through the redox cycle of quinone and applied to pharmaceutical analysis. Thirdly, a photo-induced chemiluminescence method was developed based on formation of reactive oxygen species and fluorophore or chemiluminescence enhancer by the photoreaction of quinones and applied to biological and environmental analyses.