Fe3O4-grafted nitrogen-doped graphene (Fe3O4/N-G) nanomaterials were synthesized by chemical co-precipitation method, and its adsorption properties were discussed preliminarily.It was demonstrated that the adsorption of parachlormetaxylenol on Fe3O4/N-G was not limited to uniform monolayer adsorption and the adsorption kinetic followed the pseudo-second-order kinetic mode.Then, an ultrasound-assisted magnetic solid-phase extraction with Fe3O4/N-G as the magnetic adsorbent has been developed for the determination of four compounds including triclosan, chloroxylenol, hexachlorobenzene and 2,2′,4,4′,5,5′-hexachlorobiphenyl in environmental water samples, in combination with gas chromatography coupled to tandem mass spectrometry.Several factors related to extraction efficiencies, such as the amount of adsorbent, extraction time, sample pH and desorption conditions were investigated.The proposed preparation procedure was as follows: 6.0 mg of Fe3O4/N-G was dispersed into 100 mL of water sample under ultrasound.After 15 s, the Fe3O4/N-G carrying four compounds was separated from the water sample by an external magnetic field.Then, the targets were eluted from Fe3O4/N-G with 3 mL of ethanol and 2 mL of dichloromethane, sequentially.Finally, the eluent was dried under a mild stream of nitrogen and reconstituted with methanol and dichloromethane (1∶1, V/V) for the subsequent GC-MS/MS analysis.Under the optimized condition, an excellent linearity was observed in the range of 0.1-10 ng/L for the four compounds, with the correlation coefficients ranging from 0.9983 to 0.9999.The limits of detections (S/N=3) ranged from 0.05 to 0.6 ng/L and the limits of quantity (S/N=10) ranged from 0.2 to 2.4 ng/L.The mean recoveries at three spiked levels ranged from 68.2% to 99.6%.The relative standard deviations (RSDs) of intraday and interday were in the range of 3.3%-6.9% and 3.4%-9.4% (n=6), respectively.The proposed method was demonstrated to be simple and feasible for the trace analysis of antimicrobial agents and organochlorine contaminants in environmental water samples.

OBJECTIVETo determine the structures and contents of the volatile components of flowers of Fritillaria thunbergii, and investigate the effects of operation modes on its volatile components.

METHODThe volatile oils were first obtained by the hydrodistillation assay and then submitted to gas chromatography-time-of flight mass spectrometry (GC-TOF-MS) analysis.

RESULTMore than 60 peaks were resolved, and 39 of which were identified quantitatively and qualitatively based on high-resolution spectra and compounds library screening. Among these identified components, the octadecatrienoic acid methyl esters were major components in the unprocessed flowers, while some aromatic aldehydes and ketones, such as benzeneacetaldehyde and 1-(2-hydroxy-5-methylphenyl)-ethanone, were prominent components in the flowers both dried in the fluidized bed and in shadow. In addition, the flowers dried in the fluidized bed were more fragrant than other flowers.

CONCLUSIONThe component and contents closely related to their processing mode, and the fluided bed drying may be a best choice to process the flowers of F. thunbergii.

Flowers ; chemistry ; Fritillaria ; chemistry ; Gas Chromatography-Mass Spectrometry ; methods ; Oils, Volatile ; analysis ; isolation & purification ; Plant Extracts ; analysis ; isolation & purification

Objective To investigate the operation status and service level of radiation occupational health inspection institutions in Zhejiang Province, China, and to provide a basis for administrative departments and quality management departments to develop policies. Methods The investigation data of radiation occupational health inspection institutions in Zhejiang Province were collected for descriptive analysis of the regional distribution, nature, and service qualification of the institutions. Results There were 27 radiation occupational health inspection institutions in Zhejiang Province. These institutions were located in 11 cities, of which 85.18% were public institutions and 14.72% were private institutions. For the physical examination workload of radiation workers in Zhejiang Province in 2021, general hospitals accounted for 75.90%, private institutions accounted for 4.51%, and occupational prevention and treatment hospitals accounted for 19.59%. In the radiation occupational health inspection institutions, the stand-alone and online software installation rates were 33.33% and 37.04%, respectively. A total of 26 986 individuals (82.97%) underwent chromosome aberration examination. The examination rates of thyroid color Doppler ultrasound examination and eye lens examination were 41.24% and 82.97%, respectively. Pre-job, on-job, and off-job physical examination accounted for 25.81%, 70.52%, and 3.67%, respectively. For radiation workers who underwent on-job physical examination, diagnostic radiology workers accounted for the highest proportion of 34.90%. The excellent, qualified, and unqualified rates of 27 radiation occupational health inspection institutions were 7.41%, 88.89%, and 3.70%, respectively. Conclusion The network of radiation occupational health inspection institutions in Zhejiang Province is well-established and located mainly in general hospitals, occupational prevention and control institutions, and private institutions. To enhance the quality and proficiency of occupational health examinations, it is imperative to prioritize self-improvement and management, reinforce law enforcement supervision, actively engage in blind sample assessments, and advance the application of information technology and standardized services.

Background Excessive radon exposure is considered the second risk factor for lung cancer. Since the opening of the subway in a city of Zhejiang Province, the exposure level of radioactive gas radon in subway stations and its impact on occupational health have become one of the important issues of public concern. Objective To monitor the radon concentration of subways in a city in Zhejiang Province and explore the effect of radon exposure on chromosome aberration and micronuclei in the working population. Methods A total of 55 vehicle control rooms of 55 stations affiliated to two different subway lines in a city were measured for one year; the 110 ticket offices and 55 security checkpoints from the same 55 stations were measured from 16 March to 14 June. The radon concentrations were compared by job types, subway lines, and seasons referring to Measurement methods for determination of radon in environmental air (HJ 1212-2021). Peripheral blood lymphocyte chromosome aberration and micronucleus analyses were conducted in 165 subway workers from monitoring sites for three different job types, then the influencing factors were analyzed. The detection methods were adopted from the standards of Test and assessment of chromosomal aberrations on occupational health examinations for radiation workers (GBZ/T 248-2014) and Standard for the method of micronucleus detection in lymphocytes on occupational health examination for radiation workers and exposure dose estimation (GBZ/T 328-2023). Results The radon concentration range of the target subways in Zhejiang Province was 10-320 Bq·m⁻³, all lower than the national limit (≤400 Bq·m⁻³). The differences in radon radioactivity levels among different lines, job types, and time segments were statistically significant (P<0.05). The rates of chromosomal aberration and micronucleus formation among the 165 subjects were 0.224% and 0.024%, respectively. There were significant differences in the rates of chromosome aberration and micronuclei among different jobs (vehicle control room, ticket office, security checkpoint) (P<0.05), but the abnormal rates were lower than the limits of the corresponding national standard. No significant correlation was found between jobs and chromosomal aberrations or micronuclei (P>0.05). Chromosome aberration and micronuclei varied by age, subway station seniority, and smoking (P<0.05). No effect of the above factors on chromosome aberration and micronuclei was observed by logistic regression (P>0.05). Conclusion The radon concentration in the target subway system is at a normal level. The rates of chromosomal aberration and micronucleus formation vary by jobs, but both are lower than the corresponding national limits. Therefore, radon exposure has not yet caused outstanding health impact on the subway workers.