Study of PM2.5 in Beijing suburban site by neutron activation analysis and source apportionment

Airborne particulate matter (APM) was collected in coarse fraction and in PM_2.5 during spring of 2002 in Beijing suburban sampling site by Gent SFU sampler. More attention has been paid to the special “events” such as dust, storm and haze. Taking advantage of the combination of thermal or epithermal neutron irradiation with Compton suppression spectrometer system, twenty elemental (Al, Si, Ca, K, Dy, Cu, I, In, Ba, W, Sn, Sb, As, Ti, Br, V, Mn, Cl, Na, Zn) concentration were determined. Among them, several key trace elements that cannot be accomplished by the traditional neutron activation analysis (NAA) were determined. The analysis of trace elemental concentration in PM_2.5 shows that the anthropogenic elements such as As, In, Sn, Sb have different trends than crustal elements. The back-trajectories of the high concentration anthropogenic pollution elements revealed their source region. Six potential sources were resolved by positive matrix factorization (PMF), two area type and four source type, as soil, limestone quarry, crop burning and mixture of residue motor and coal burning sampling sites. Taking into account of everyday air particle back trajectories, source compositions together with source regions were also identified. This revised version was published online in July 2006 with corrections to the Cover Date.     

Characterization of the aeolian aerosol from Cape Verde by k 0-INAA and PIXE

Due to its location on West Coast of Africa, Cape Verde is highly influenced by Sahara Desert dust events being an optimum place to observe and study the African aeolian aerosol. During 2011, particulate matter with an aerodynamic diameter lower than 10 μm (PM₁₀) was sampled in Santiago Island and its chemical composition was evaluated by k ₀-instrumental neutron activation analysis (k ₀-INAA) and particle induced X-ray emission (PIXE). This study showed the existence of a seasonal intrusion of dust from Africa (that occurred from October to March) characterized by significant increases of PM₁₀, mineral elements and anthropogenic particles concentrations. In 2011, the PM₁₀ health-based air quality guidelines defined by WHO, EU and USEPA were exceeded. Cape Verde PM₁₀ composition was characterized essentially by high concentrations of elements originating from the soil (Ca, Ce, Co, Fe, K, Mg, Mn, Rb, S, Sc, Si, Sm, and Ti) and sea (Br, Cl, and Na); and low concentrations of anthropogenic elements (As, Cr, Cu, Ni, Pb, Sb, V, and Zn). k ₀-INAA and PIXE were fundamental tools for the determination of airborne chemical elements in Cape Verde. Their multi-elemental capabilities in association with low detection limits made it possible to determine the majority of the element concentrations of environmental interest.     

Work place air particulate monitoring of automobile workshops for public health and safety

Twenty-eight pairs of coarse and fine air particulate samples were collected in front of an automotive workshop located at Tasmasipabad on Chaklala Road in Rawalpindi using a Gent sampler and polycarbonate filters. These samples were collected during the period; 7th to 27th of April 2009. The gravimetric data (PM_2.5 and PM₁₀) were obtained for these samples and were found to exceed the Pakistani standards. Black carbon (BC) was also determined using reflectance measurements and it was found that BC contributed significantly more to the fine mass than to the coarse fraction; i.e. ~10 to ~3 %, respectively. This is not surprising as soot is emitted by combustion processes and is usually found in the fine particulate mass. Using instrumental neutron activation analysis technique all 28 pairs of filters were analyzed for >30 elements. Major elements, in the coarse mass fraction, include Al, K, Fe, Sr, Na, and Zn implying soil as the major source while BC was found to be a higher contributor of PM_2.5. An episode of high PM_2.5 was observed on the 18th of April 2009. Back trajectory analysis showed that the air mass originated from the Middle East where a dust storm was in progress over Iraq.     

Determination of chemical elements in airborne particulate matter collected at Lembang, Indonesia by particle induced X-ray emission

Monitoring the air quality in ambient air is an important step for assessing the air pollution level in one region and its impact to the human health. In this study, the determination of chemical elements concentrations in airborne particulate matter collected in suburban area of Lembang, Indonesia was carried out. Samples were collected using a Gent stacked filter unit sampler in two size fractions of <2.5 μm (fine) and 2.5–10 μm (coarse). Sampling was conducted twice a week for 24 h from January 2008 to June 2009 and 123 pairs of samples were collected. Black carbon was determined by reflectance and chemical elements analysis were performed using particle induced X-ray emission (PIXE). PIXE as one of ion beam analysis techniques is suitable for analyzing particulate matter for its multielemental analysis with good limits of detection. Results showed that none of daily concentrations of PM_2.5 and PM₁₀ exceeded the 24 h Indonesian NAAQS for PM_2.5 and PM₁₀. Chemical elements such as Mg, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Hg and Pb were determined and the correlation between these elements was reported in order to understand the anthropogenic sources of particulate matter.     

Local and non-local sources of airborne particulate pollution at Beijing

A new element tracer technique has firstly been established to estimate the contributions of mineral aerosols from both inside and outside Beijing. The ratio of Mg/Al in aerosol is a feasible element tracer to distinguish between the sources of inside and outside Beijing. Mineral aerosol, inorganic pollution aerosol mainly as sulfate and nitrate, and organic aerosol are the major components of airborne particulates in Beijing, of which mineral aerosol accounted for 32%–-67% of total suspended particles (TSP), 10% –70% of fine particles (PM2.5), and as high as 74% and 90% of TSP and PM_2.5, respectively, in dust storm. The sources from outside Beijing contributed 62% (38%–-86%) of the total mineral aerosols in TSP, 69% (52%–-90%) in PM₁₀, and 76% (59%–-93%) in PM_2.5 in spring, and 69% (52%–-83%), 79% (52%–-93%), and 45% (7% – 79%) in TSP, PM₁₀, and PM_2.5, respectively, in winter, while only ≈20% in summer and autumn. The sources from outside Beijing contributed as high as 97% during dust storm and were the dominant source of airborne particulates in Beijing. The contributions from outside Beijing in spring and winter are higher than those in summer, indicating clearly that it was related to the various meteorological factors.     

Competitive immunoassay for monitoring polybrominated diphenyl ethers in PM2.5 in Shanghai

In this paper, a sensitive biotin–streptavidin (BS)-ELISA was developed for determining the polybrominated diphenyl ethers in PM_2.5. For establishing this proposed BS-ELISA, we prepared the biotinylated antibody primarily. And for reducing the background interference, some in?uencing factors and procedures for this immunoassay were also discussed and optimised. Under the optimal conditions, the IC₅₀ = 0.53 ng/mL; IC₁₀ was 0.002 ng/mL; and the results were almost consistent with those using the gas chromatography and electron capture detection (GC-ECD). Less procedures and simpler sample preparation were required for this method compared with the GC-ECD. The results showed that the highest value of BDE-47 concentration occurred in December, which might re?ect the combination of heating and industrial pollution. In our analysis, we studied the Pearson correlations between BDE-47/PM_2.5 and gaseous pollutants (such as NO₂, SO₂, CO, O₃, PM₁₀ and PM_2.5). BDE-47 showed a higher correlation with NO₂ than that with PM₁₀, PM_2.5 and SO₂, which implied that the BDE-47 emission process might be accompanied by the emission of NO₂. Moreover, during the Spring Festival, the concentration of BDE-47 in PM_2.5 decreased significantly, whereas the PM_2.5 changed little. This suggested factories and vehicles might be the major contributors to BDE-47 emissions (but not to PM_2.5).     

Recent trends of plutonium fallout observed in Japan: Comparison with natural lithogenic radionuclides, thorium isotopes

PM_2.5 and PM₁₀ samples were simultaneously collected monthly at a downtown site in Beijing from May 2002 to April 2003 and analyzed by instrumental neutron activation analysis (INAA) combined with organic solvent extraction method for the concentrations and distributions of extractable organohalogens (EOX), including extractable organochlorinated (EOCl), organobrominated (EOBr) and organoiodinated compounds (EOI). The concentrations of EOCl, EOBr and EOI were 10.5–79.2 ng/m³, ND-8.2 ng/m³ and 1.6–8.2 ng/m³ in PM_2.5, respectively, and 37.0–73.3 ng/m³, 1.6–12.8 ng/m³ and 1.6–8.5 ng/m³ in PM₁₀, respectively, which were increasing in the order of EOCl≫EOBr∼EOI. EOCl accounted for 73–88% and 69–91% of EOX in PM_2.5 and PM₁₀, respectively, which showed that EOCl was the major component of the organohalogens. There was a significant difference of EOCl concentrations in PM_2.5 and PM₁₀ in different seasons, which suggested that the concentrations of EOCl in the atmosphere were significantly affected by the meteorologic conditions and anthropogenic activities.     

Portable,Ambient PM2.5 Sensor for Human and/or Animal Exposure Studies

A field-portable device for logging PM_2.5 mass concentration data has been developed. The device combines the Arduino microprocessor with an SD card, a Sharp DN7C3CA006 optical dust monitor, and 10,000-mAh battery. The dust sensor uses a virtual impactor to size select particles <2.5 microns prior to illuminating the selected fraction with an LED. The LED is triggered by a circuit controlled with the Arduino. Nephelometric detection at 120° referenced to incidence is used. The voltage signal reported by the dust sensor is converted to PM_2.5 mass through calibration onboard the Arduino. Data points can be saved to the SD card as rapidly as 0.3?s, although averaging signals over 60?s produced more optimal detection limits. For a 60?s average, the PM_2.5 mass limit of detection was 9?µg?m^?3, indicating that the sensor will be useful for monitoring human exposure to fine particles. Portable exposure monitoring has been demonstrated with the sensing platform as several individuals carried the device with them during daily activities in Lubbock, TX and Atlanta, GA. For this group of test subjects, values of PM_2.5 exposure varied from 0 to 1000?µg?m^?3 during the sampling periods. It was observed that, by far, the highest levels of PM_2.5 occur during periods of cooking, or being near cooking operations. Other periods of high PM_2.5 occurred during ground transportation, use of personal care products, vacuuming, and visiting restrooms. When hourly personal exposure data were correlated with hourly average PM_2.5 for outdoor air for the Atlanta data set, a very weak correlation was found (R²?=?0.026). Only two out of eight sampling periods did the personal monitoring estimate of exposure agree with that predicted by outdoor monitoring to within 15%. Personal exposure was often affected by circumstantial, short-term, high exposure events that are difficult to model or predict effectively. The short-term exposure events generally cause true exposure to be higher than that predicted by using outdoor ambient PM_2.5 to generate estimates. This finding complicates interpretation of epidemiological studies that find links between ambient outdoor PM_2.5 levels and human health, while it buttresses the case for using personal ambient monitors.     

Elemental concentrations of aerosols near Portuguese power plants by INAA and PIXE

Mass and elemental concentrations in PM₁₀ and PM_2.5 — airborne particulate matter with an aerodynamic diameter below 10 μm and 2.5 μm, respectively — have been evaluated in mainland Portugal since 1993. The data herein refer to areas generally impacted by emissions from electrical power plants, either coal- or oil-fired, which are mostly large, state-of-the-art facilities. Background areas have been sampled as well, and results from one of them are given for comparison. Through the country, lead levels are well below the European enacted values, particularly since unleaded fuels became mandatory in the late 1990s. Nickel appears especially concentrated in PM_2.5 and, apart from extreme cases (rural sites, coal-fired plants), its levels are not significantly different from place to place. Highest values for arsenic and mercury have been found in the vicinity of the coal-fired plants. Cadmium data, if only available for metropolitan Lisbon, seems to confirm the trend for anthropogenic elements appearing mainly in fine particulates.     

Source identification and long-term monitoring of airborne particulate matter (PM<Subscript>2.5</Subscript>/PM<Subscript>10</Subscript>) in an urban region of Korea

Summary For the identification of air pollution sources, about 500 airborne particulate matter (PM_2.5and PM₁₀) samples were collected by using a Gent air sampler and a polycarbonate filter in an urban region in the middle of Korea from 2000 to 2003. The concentrations of 25 elements in the samples were measured by using instrumental neutron activation analysis (INAA). Receptor modeling was performed on the air monitoring data by using the positive matrix factorization (PMF2) method. According to this analysis, the existence of 6 to 10PMF factors, such as metal-alloy, oil combustion, diesel exhaust, coal combustion, gasoline exhaust, incinerator, Cu-smelter, biomass burning, sea-salt, and soil dust were identified.     

Use of INAA and PIXE for multipollutant air quality assessment and management

The objective of this paper was to assess the air pollution and the main sources of Air Particulate Matter in the Setúbal urban/industrial area, Portugal. PM_2.5 and PM_2.5?C10 were sampled in Nuclepore filters and lichens transplants were exposed during 9?months. The levels of elements in these two matrixes were measured by INAA and PIXE. A large data base was created and source apportionment was performed by using Principal Component Analysis. The results showed that the main sources of fine particles were anthropogenic and were related with traffic and local industry. There was an important contribution of natural sources, mainly for the coarse fraction, associated with the sea and the soil. Lichens characterization and mapping showed that different site-specific characteristics controlled the spatial distribution of different elements. This study showed that biomonitoring is an effective complementary method to traditional sampling systems.     

Assessment of the sources of the inorganic fraction of aerosol in a conurbation

Two intensive sampling campaigns for coarse (PM_2.5–10) and fine (PM_2.5) particulate matter were carried out in August 2003 and March 2004 in the multi-impacted centre of the Athens (Greece) conurbation. Receptor modelling by means of Positive Matrix Factorization was utilised in order to provide an insight to the poorly characterised sources of the chemically analysed inorganic fraction of the sampled aerosol mass. Using elemental concentrations, seven factors have been resolved for both fractions for August 2003. Combining elemental and ionic concentrations, nine factors were resolved in the coarse particulate matter and eight in the fine particulate matter for March 2004. The greatest contributors of primary origin are (re)suspended dust/soil and sea salt. Secondary aerosol contributions were resolved in the form of secondary sulphate, secondary nitrate as well as an aged sea salt factor which was characterised by the replacement of chloride with sulphate and, secondarily, nitrate. Furthermore, throughout sites and fractions, primary anthropogenic emissions were identified in a series of factors, including a Pb-rich profile, representing non-catalytic exhaust emissions, a Cu-Mo-Sb-rich profile representing brake emissions, a Zn-Ba-rich profile representing tyre-wear and heavy vehicle brakes, and, lastly, a V-Ni-rich factor representing industrial heavy oil-combustion. Local anthropogenic emissions predominated, outweighing long-range transport as it was suggested by the lack of direct relationship between changes in the wind speed and direction and species mass burdens, as well as factor contributions.     

Study of the chemical composition of particulate matter from the Rio de Janeiro metropolitan region,Brazil, by inductively coupled plasma-mass spectrometry and optical emission spectrometry

Air quality in the metropolitan region of Rio de Janeiro was evaluated by analysis of particulate matter (PM) in industrial (Santa Cruz) and rural (Seropédica) areas. Total suspended particles (TSP) and fine particulate matter (PM_2.5) collected in filters over 24 h were quantified and their chemical composition determined. TSP exceeded Brazilian guidelines (80 μg m^− 3) in Santa Cruz, while PM_2.5 levels exceeded the World Health Organization guidelines (10 μg m^− 3) in both locations. Filters were extracted with water and/or HNO₃, and the concentrations of 20 elements, mostly metals, were determined by inductively coupled plasma mass spectrometry (ICP-MS) and optical emission spectrometry (ICP OES). Water soluble inorganic anions were determined by ion chromatography (IC). To estimate the proportion of these elements extracted, a certified reference material (NIST SRM 1648a, Urban Dust) was subjected to the same extraction process. Concordant results were obtained by ICP-MS and ICP OES for most elements. Some elements could not be quantified by both techniques; the most appropriate technique was chosen in each case. The urban dust was also analyzed by the United States Environmental Protection Agency (US EPA) method, which employs a combination of hydrochloric and nitric acids for the extraction, but higher extraction efficiency was obtained when only nitric acid was employed. The US EPA method gave better results only for Sb. In the PM samples, the elements found in the highest average concentrations by ICP were Zn and Al (3–6 μg m^− 3). The anions found in the highest average concentrations were SO₄^2 − in PM_2.5 (2–4 μg m^− 3) and Cl⁻ in TSP (2–6 μg m^− 3). Principal component analysis (PCA) in combination with enrichment factors (EF) indicated industrial sources in PM_2.5. Analysis of TSP suggested both anthropogenic and natural sources. In conclusion, this work contributes data on air quality, as well as a method for the analysis of PM samples by ICP-MS.     

杭州市冬季大气气溶胶PM2.5中二恶英和多氯联苯的污染特征

2014年1月在杭州市选择5个点位采集大气颗粒物PM_2.5样品,采用同位素稀释高分辨气相色谱/高分辨质谱测定PM_2.5中的二恶英（PCDD/Fs）和多氯联苯（PCBs）,对PM_2.5的污染状况以及PM_2.5中PCDD/Fs和PCBs的污染水平及分布特征进行了研究。PM_2.5的质量浓度范围为85~168 μg/m³,PM_2.5污染较重,但与2004年同期相比明显降低。PM_2.5中PCDD/Fs的毒性当量（TEQ）为0.277~0.488 pg I-TEQ/m³,明显高于2004年同期采集样品。颗粒物中PCDD/Fs以八氯代二苯并-对-二恶英（OCDD）为主,毒性当量主要贡献者为2,3,4,7,8-五氯代二苯并呋喃（2,3,4,7,8-PeCDF）。PM_2.5中PCBs的质量浓度范围为2.9~8.1 pg/m³,二恶英类多氯联苯（DL-PCBs）的毒性当量范围为2.6~6.1 fg WHO-TEQ/m³,污染较低。PCBs在颗粒物中分布以PCB-28为主,但对毒性当量贡献最大的为PCB-126。PCDD/Fs和PCBs的气-固分配特征表现为PCDD/Fs主要分布于颗粒物中,而PCBs主要分布于气相中。     

Neutron activation analysis for identification of African mineral dust transport

A Gent stacked filter unit sampler was used to collect air particulate matter (APM) in separate coarse (PM_2.5–10) and fine (PM_2.5) size fractions, at a sub-urban site in Lisbon, Portugal. The sampling was done during the year 2001 and two daily samples were taken per week. The filters were analyzed for particulate mass by instrumental neutron activation analysis (INAA). The chemical analysis of APM levels and the study of the atmospheric dynamics by back-trajectories showed that most of the PM_2.5 and PM_2.5–10 peaks events were associated with air masses transport from the Saharan desert. High mineral load in ambient particulate matter levels were registered during the Saharan dust outbreaks. The accuracy of INAA to measure Fe, Sc and Sm was evaluated by NIST filter standards, revealing results with an agreement of ± 10%. This method constituted an important tool to identify these events.     

Characterizing air particulate matter composition and sources in Lisbon,Portugal

The goal of this research is to determine trends and sources of airborne particulates in the centre of Lisbon, by using speciated particulate-matter data and back-trajectory analyses. Results showed that, in 2007, the annual PM_2.5 concentration exceeded the World Health Organization recommended levels. PM_2.5 diurnal variability and the ratio between weekdays’ and weekends’ concentrations indicated that traffic contributed highly to decreasing air quality. Air back-trajectory analysis showed that maritime air mass transport had a significant role on air quality in Lisbon, promoting the decrease of anthropogenic aerosol concentrations.     

Bioaccessibility of selected trace metals in urban PM<Subscript>2.5</Subscript> and PM<Subscript>10</Subscript> samples: a model study

Bioaccessibility of trace metals originating from urban particulate matter was assessed in a worst case scenario to evaluate the uptake and thus the hazardous potential of these metals via gastric juice. Sampling was performed over a period of about two months at the Getreidemarkt in downtown Vienna. Concentrations of the assayed trace metals (Ti, Cr, Mn, Co, Ni, Cu, Zn, Mo, Ag, Cd, Sn, Sb, Tl and Pb) were determined in PM_2.5 and PM₁₀ samples by ICP-MS. The metal concentrations in sampled air were in the low picogram to high nanogram per cubic metre range. The concentrations in PM_2.5 samples were generally lower than those in PM₁₀ samples. The average daily intake of these metals by inhalation for a healthy adult was estimated to be in the range of <1 ng (Tl) to >1,000 ng (Zn). To estimate the accessibility of the inhaled and subsequently ingested metals (i.e. after lung clearance had taken place) in the size range from 2.5- to 10-μm aerodynamic equivalent diameter, a batch-extraction with synthetic gastric juice was performed. The data were used to calculate the bioaccessibility of the investigated trace metals. Extractable fractions ranged from 2.10% (Ti in PM_2.5) to 91.0% (Cd in PM_2.5), thus yielding bioaccessible fractions (PM_2.5–10) from 0.16 ng (Ag) to 178 ng (Cu).     

Comparative study of bulk and partial digestion methods for airborne PM10-bound elements in a high mineral dust urban site in Constantine,Algeria

When high mineral loads in atmospheric particulate matter (PM) are present, particular attention should be paid to the selection of appropriate acidic digestion protocols for wet chemical analysis. We report on a comparative study of elemental recovery yields from five different pre-analytical acid digestion procedures for mineral-rich urban background PM₁₀ samples collected in the city of Constantine (Northeastern Algeria). Five reference materials (NIST 1633b, UPM 1648, NAT-7, SO-2 and SO-4) were also digested according to the same protocols. The selected acidic digestion/extraction procedures are widely used for PM chemical analysis and comprise P1 (HNO₃/HF/HCl), P2 (HCl/HNO₃), P3 (HCl/H₂O₂/HNO₃), P4 (HNO₃/HF/HClO₄) and P5 (HNO₃/H₂O₂); the latter assisted with microwave digestion. Elemental recovery yields were compared for major and trace elements typically determined in PM for source apportionment analysis and the results evidenced large differences. For most elements, the bulk extraction procedures (requiring the use of HF) allowed a full elemental recovery, particularly for elements that are associated with aluminium silicate species and oxides that are resistant to mild acid attack. In contrast, in the extraction protocols without HF low recovery yields were obtained for elements such as Al, Ti, Zr, Sc and other aluminium silicate-related elements in PM₁₀ samples with high mineral dust load. We highlight that the European standard digestion method EN-14902:2005 should be applied specifically for the metals for which this method was developed, but caution should be taken when the analysis of other elements in PM is required, especially in urban areas where road and vehicle wear dust is likely to be a major component of ambient PM. When using wet chemistry analysis for PM source apportionment studies, we strongly recommend HF bulk dissolution of samples to ensure the reliability of the geochemical information when coupled with an appropriate analytical tool.     

Pollution characteristics of atmospheric fine particles and their secondary components in the atmosphere of Shenzhen in summer and in winter

Two field measurements for atmospheric fine particles were conducted in Baoan district of Shenzhen during the summer and winter in 2004. Totally 30 sets of 24 h samples were collected, and then the mass concentrations and chemical compositions were determined. The seasonal varia- tions and secondary pollution characteristics of fine particles during the sampling periods were dis-cussed with meteorological factors. The results show that seasonal variations of atmospheric particles are significant in Shenzhen. The average mass concentrations of PM2.5 and PM10 in summer were 35 μg·m-3 and 57 μg·m-3, respectively, and those in winter were 99 μg·m-3 and 135 μg·m-3, respec-tively. The concentrations of both PM2.5 and PM10 in winter increased 184% and 137%, respectively, compared to those in summer. PM2.5 accounted for 61% and 75% of PM10 in summer and in winter, respectively, indicating severe fine particle pollution in Shenzhen. During the summer and winter sampling periods, the mean OC/EC ratios were 3.4 and 1.6, respectively. The estimated secondary organic carbon (SOC) averagely accounted for 56% and 6% of the total OC in summer and in winter, respectively, which implies a major contribution of SOC to OC in summer. During the continuous high temperature period in summer, both the concentrations and fractions of secondary aerosol compo-nents in PM2.5 were highly elevated, suggesting severe secondary pollution again. The prevailing wind was from South China Sea in summer, and the air quality was good. The prevailing wind in winter was from Mainland China to the north, and the polluted air mass led to poor air quality.     

离子色谱-电感耦合等离子体质谱联用测定大气颗粒物PM2.5和PM10中的六价铬

建立了大气颗粒物PM_2.5、PM₁₀中六价铬（Cr（Ⅵ））的离子色谱-电感耦合等离子体质谱（IC-ICP-MS）检测方法。采用碳酸氢钠（NaHCO₃）溶液超声提取大气颗粒物样品中的Cr（Ⅵ）,并使用含有0.22 g/L 乙二胺四乙酸二钠盐（Na₂EDTA）的75 mmol/L硝酸铵溶液（pH 7.0）淋洗液通过离子色谱柱（AG7,50 mm×4 mm）分离出样品中的Cr（Ⅵ）,电感耦合等离子体质谱测定。标准溶液中Cr（Ⅵ）的质量浓度在0.05~5 μg/L范围内呈良好的线性关系,相关系数达0.9999,标准溶液测定的精密度为1.0%~4.0%,标准样品测定的相对误差为3.3%;纤维素滤膜适用于Cr（Ⅵ）的采样,将纤维素滤膜碱化后,Cr（Ⅵ）的回收率从75%增加到102%;样品在20 mmol/L碳酸氢钠溶液中超声30 min后上机测试,提取完全且回收率稳定;当采样体积为20 m³,方法的检出限为0.0004 ng/m³;采集并测定了PM_2.5及PM₁₀实际样品,样品的加标回收率为91.6%~102%,精密度为1.7%~7.6%。该方法高效、稳定、灵敏,适用于大气颗粒物中六价铬的测定。