Jilin Meteorological Bureau

Abstract A dataset of 282 meteorological stations including all of the ordinary and national basic/reference surface stations of north China is used to analyze the urbanization effect on surface air temperature trends. These stations are classified into rural, small city, medium city, large city, and metropolis based on the updated information of total population and specific station locations. The significance of urban warming effects on regional average temperature trends is estimated using monthly mean temperature series of the station group datasets, which undergo inhomogeneity adjustment. The authors found that the largest effect of urbanization on annual mean surface air temperature trends occurs for the large-city station group, with the urban warming being 0.16°C (10 yr)−1, and the effect is the smallest for the small-city station group with urban warming being only 0.07°C (10 yr)−1. A similar assessment is made for the dataset of national basic/reference stations, which has been widely used in regional climate change analyses in China. The results indicate that the regional average annual mean temperature series, as calculated using the data from the national basic/reference stations, is significantly impacted by urban warming, and the trend of urban warming is estimated to be 0.11°C (10 yr)−1. The contribution of urban warming to total annual mean surface air temperature change as estimated with the national basic/reference station dataset reaches 37.9%. It is therefore obvious that, in the current regional average surface air temperature series in north China, or probably in the country as a whole, there still remain large effects from urban warming. The urban warming bias for the regional average temperature anomaly series is corrected. After that, the increasing rate of the regional annual mean temperature is brought down from 0.29°C (10 yr)−1 to 0.18°C (10 yr)−1, and the total change in temperature approaches 0.72°C for the period analyzed.

Based on homogeneity-adjusted daily temperature data from national stations, the spatial and temporal change in extreme temperature events in mainland China have been analyzed for the period 1961-2008. The analysis shows that the numbers of frost days and ice days were significantly reduced, with the most significant reduction generally in northern China for ice days but more extensively across the country for frost days. Summer days and tropical nights significantly increased along the middle and lower reaches of the Yangtze River and in southern Southwest China. The maximum values of T max (TXx) and T min (TNx) and the minimum values of T max (TXn) and T min (TNn) generally rose, and TXx and TNx significantly increased in northern China, while TXn and TNn significantly increased across the whole country. A significant reduction at a rate of -8.23 d decade -1 (-3.26 d decade -1 ) occurred for cool nights (days), and a significant increase at a rate of 8.16 d decade -1 (5.22 d decade -1 ) occurred for warm nights (days). The reduction of cool nights and cool days occurred mainly in winter, but the increase of warm days and warm nights occurred mostly in autumn and summer. Extreme cold indices were reduced, mainly after the mid-1980s, while extreme warm indices increased remarkably after the mid-1990s. The analysis also shows that, for North China, the urbanization effect on the series of extreme temperature indices was statistically significant for the negative trends of frost days, diurnal temperature range, cool nights and cool days, and for the positive trends of summer days, tropical nights, TNx, TNn, and warm nights.

Land use/land cover (LULC) change has greatly altered ecosystem carbon storage capacity and can eventually profoundly impact global climate change. Characterizing the LULC change and its impact on ecosystem carbon storage in coastal areas is greatly significant to comprehensively understanding the influences of human activities on ecosystems. Based on LULC data, this paper combined CA-Markov and InVEST models to evaluate the past, present, and future LULC change and its impact on ecosystem carbon storage in coastal areas of China. The results showed that past LULC change in coastal areas can be divided into two stages: (I) accelerated evolution stage (1980–2010), and (II) stable evolution stage (2010–2020). Changes in LULC types have led to a downward trend in ecosystem carbon storage, with a cumulative loss of 0.39 Pg and 0.15 Pg during the two stages, respectively. Spatially, carbon storage presented a high-low-high spatial distribution pattern from north to south. Temporally, areas with a rapid urbanization process exhibited more obvious changes in carbon storage dynamics. Compared with the natural change scenario, the areas with LULC types conversion under the ecological conservation scenario in 2050 will be lower due to the limitation of ecological protection, and it caused carbon storage reduction will slow down. Rapid LULC dynamics, that a large area of farmland, unused land and, water have been converted into construction land, reduced the carbon sequestration capacity of the ecosystem. This study will provide reliable references and precise data support for coastal management and decision-making.

BACKGROUND: The optimal trastuzumab-based chemotherapy regimen for HER2-overexpressing, metastatic breast cancer is not known. The trastuzumab and vinorelbine or taxane (TRAVIOTA) study was a prospective, multicenter, randomized trial that was designed to compare these regimens. METHODS: Eligible patients had HER2-overexpressing, metastatic breast cancer and had received no prior chemotherapy for advanced disease. Patients were randomized 1:1 to receive either trastuzumab with weekly vinorelbine therapy or weekly taxane therapy (paclitaxel or docetaxel at the investigator's choice). Originally planned for 250 patients, the study was closed because of poor accrual with 81 evaluable patients, including 41 patients who received vinorelbine and 40 patients who received taxane. RESULTS: Response rates were 51% and 40% for the vinorelbine/trastuzumab arm and the taxane/trastuzumab arm, respectively (Fisher exact test; P = .37). The median time to disease progression was 8.5 months and 6.0 months for the vinorelbine- and taxane-based arms, respectively (log-rank test; P = .09). Treatment with either regimen generally was well tolerated, yielding comparable rates of neurologic and gastrointestinal toxicity. Vinorelbine-based treatment was associated with more anemia and neutropenia and with 2 episodes of cardiotoxicity. Taxane-based therapy was associated with more dermatologic toxicity, myalgias, and fluid retention. CONCLUSIONS: Both vinorelbine/trastuzumab and taxane/trastuzumab treatments were active as first-line therapy for HER2-positive, metastatic breast cancer and had comparable rates of efficacy and tolerability. The toxicities observed were the result of recognized side effects associated with each of the chemotherapy agents and schedules. These data can inform treatment decision making in this clinical setting.

A previous study revealed a close relationship between interannual variations ofnortheast China (NEC) summer temperature and a tripole sea surface temperature (SST)anomaly pattern in the North Atlantic in preceding spring. The present study investigatesthe change in the above relationship and the plausible causes for the change. A tripole SSTindex is defined with its positive value corresponding to positive SST anomalies in thetropics and midlatitudes and negative SST anomalies in the subtropics. The tripole SSTanomaly pattern has a weak correlation with NEC summer temperature during the 1950sthrough the mid‐1970s, in sharp contrast to the 1980s and 1990s. This change is related tothe difference in the persistence of the tripole SST pattern. Before the late 1970s, thetripole SST pattern weakened from spring to summer, and thus, the spring North Atlantictripole SST pattern had a weak connection with NEC summer temperature. On thecontrary, after the late 1970s, the tripole SST pattern displayed a tendency of persistencefrom spring to summer, contributing to circulation changes that affected NEC summertemperature. There are two factors for the persistence of the tripole SST pattern fromspring to summer. One is the North Atlantic air‐sea interaction, and the other is thepersistence of SST anomalies in the eastern equatorial Pacific during the decay ofEl Nino–Southern Oscillation (ENSO). It is shown that the North Atlantic SST anomaliescan have an impact on NEC summer temperature independent of ENSO.

Warm conveyor belts (WCBs) and frontal activity play important roles in the long‐range transport of air pollutants by lifting them from the planetary boundary layer (PBL) into the free troposphere (FT) in midlatitudes. In summer 2007, an aircraft study was carried out in northeast (NE) China in order to understand the role of midlatitude cyclones in air pollution transport in north and east China in warm seasons. During a flight on 27 June, high concentrations of ozone and related trace gases were observed, with maximum concentrations (O 3 ∼ 140 ppbv, SO 2 ∼ 14.6 ppbv, CO ∼ 1185 ppbv) recorded at an altitude of 2.6 km. In this paper we present a detailed analysis of this flight. The mesoscale meteorological model Weather Research and Forecasting (WRF) and a Lagrangian dispersion model called FLEXPART were used to aid the diagnostic analysis of the atmospheric dynamic structure and the understanding of the transport characteristics of regional and local air pollution. The flight took place in a region adjacent to a warm front associated with a weak cyclone in north China. The aircraft sampled both the WCB and warm air frontal zone of the cyclone. The simulations show that the observed high air pollution in the FT mostly originated from the North China Plain, especially the megacities Beijing and Tianjin. Their plumes were vented by a stagnant front, probably through, in part, topographic lifting by the mountains in the north, and then were quickly transported in the FT to the study region. Trajectory analysis and satellite data suggest that the observed air masses were further lifted by the WCB into the middle and upper troposphere and were exported from Asia toward North America and the Arctic.

Northeast China (NEC) summer temperature tends to be lower (higher) than normal in El Niño (La Niña) developing years during 1950s through mid‐1970s. The relationship between the NEC summer temperature and El Niño‐Southern Oscillation (ENSO) is weakened or even becomes opposite in 1980s and 1990s. The present study documents this interdecadal change and investigates plausible reasons for this change. Before the late 1970s, ENSO affects the NEC summer temperature through modulating the South Asian heating and consequently the midlatitude Asian circulation. After the late 1970s, the connection between ENSO and the Indian summer monsoon and that between the South Asian heating and the midlatitude Asian circulation have been weakened. This leads to a weakening of ENSO impacts on the NEC summer temperature. It is found that the NEC summer temperature variations are closely related to the North Atlantic sea surface temperature (SST) and circulation changes in 1980s and 1990s. In particular, a tripole North Atlantic SST anomaly pattern in boreal spring is a good precursory for the NEC summer temperature anomalies. The NEC summer temperature displays a negative correlation with the summer SST surrounding the Maritime Continent in 1980s and 1990s. In many years, the tropical North Pacific and the North Atlantic SST anomalies can contribute in concert to the midlatitude Asian circulation changes and the NEC summer temperature anomalies. These effects overcome those of the central and eastern equatorial Pacific SST anomalies, leading to a same‐sign relationship between the NEC summer temperature and the central and eastern equatorial Pacific SST anomalies.

A recently derived data set of daily precipitation is used to study the summer precipitation events over Asia and their changes in the decades of 1978–2002. Regional features of the precipitation over entire tropical‐subtropical Asia are investigated, exploiting the increased resolution and improved accuracy of the data set relative to other estimates. The changes in precipitation amount and precipitation days for total, extreme, heavy, and light‐moderate precipitations are examined. Although the Asian summer monsoon precipitation falls mostly in the form of light‐moderate rainfalls, regions of relatively frequent extreme precipitation events are found over South Asia and East‐Southeast Asia. These regions are separated by a narrow zone over the Indo‐China peninsula, along 100°E, where extreme precipitation rarely occurs. During the period examined, the amount of total precipitation and light‐moderate precipitation exhibits positive trends over southeastern and northwestern China, separated by negative trends over central China and southwestern and northeastern Asia. This sandwich‐like pattern, which also appears in the fields of precipitation days and soil moisture content, is associated with the enhanced water vapor supply related to the strengthened monsoon flow over southeastern China and the anomalous easterlies over northwestern China. It is also associated with the decreased water vapor supply linked to the weakened monsoon flows over southern‐southwestern Asia and central China and to the anomalous northerly flow over northeastern Asia. Over the entire tropical‐subtropical Asia, the largest changes in precipitation, atmospheric circulation, and water vapor transport occur over southern China. On the other hand, the changes over India are much smaller.

Abstract Convolutional neural network (CNN) is an effective tool for extracting interpretable information from big data and has been recently used as a promising approach for statistical downscaling. In this study, CNN models of different configurations are used to downscale daily temperature and precipitation over China with the use of large‐scale atmospheric variables from ECMWF Interim reanalysis (ERI) and high‐resolution gridded observations as predictors and predictands respectively. A 21‐year period from 1979 to 1999 is used for calibration and a relatively warmer period during 2000–2017 is used for validation, which helps to examine the extrapolation capability of models. It is shown that model performance varies among different configurations. For a realistic multi‐site downscaling over whole China, the convolutional process is indispensable and much more spatial features are required to parameterize temperature characteristics than precipitation. As compared with ERI, CNN model shows added value in reproducing geographic distributions of seasonal mean climate and seasonal cycle as well as reducing biases in mean and extreme percentiles for both temperature and precipitation. However, ERI performs better in terms of temporal correlations. Then the model is further compared with Generalized Linear regression Model (GLM) and two quantile mapping based techniques including bias correction and spatial disaggregation (BCSD) and bias correction and climate imprint (BCCI). It is shown that bias correction methods show superior performances to other models in reducing biases and representing temporal correlations especially for precipitation. CNN model achieves better precipitation downscaling performances than GLM. It also achieves good skills in reproducing seasonal cycle of temperature and frequency distributions of daily precipitation, and presents better stabilities between the calibration and validation period. These results indicate that CNN model has good potential for downscaling application over large regions (e.g., continents).

Abstract Trends in surface air temperature (SAT) are a critical indicator for climate change at varied spatial scales. Because of urbanization effects, however, the current SAT records of many urban stations can hardly meet the demands of the studies. Evaluation and adjustment of the urbanization effects on the SAT trends are needed, which requires an objective selection of reference (rural) stations. Based on the station history information from all meteorological stations with long-term records in mainland China, an integrated procedure for determining the reference SAT stations has been developed and is applied in forming a network of reference SAT stations. Historical data from the network are used to assess the urbanization effects on the long-term SAT trends of the stations of the national Reference Climate Network and Basic Meteorological Network (RCN+BMN or national stations), which had been used most frequently in studies of regional climate change throughout the country. This paper describes in detail the integrated procedure and the assessment results of urbanization effects on the SAT trends of the national stations applying the data from the reference station network determined using the procedure. The results showed a highly significant urbanization effect of 0.074°C (10 yr) −1 and urbanization contribution of 24.9% for the national stations of mainland China during the time period 1961–2004, which compared well to results that were reported in previous studies by the authors using the predecessor of the present reference network and the reference stations selected but when applying other methods. The authors are thus confident that the SAT data from the updated China reference station network as reported in this paper best represented the baseline SAT trends nationwide and could be used for evaluating and adjusting the urban biases in the historical data series of the SAT from different observational networks.

Thymol (THY) was found to have in vitro antifungal activity against 24 fluconazole (FLC)-resistant and 12 FLC-susceptible clinical isolates of Candida albicans, standard strain ATCC 10231 and one experimentally induced FLC-resistant C. albicans S-1. In addition, synergism was observed for clinical isolates of C. albicans with combinations of THY-FLC and THY-amphotericin B (AMB) evaluated by the chequerboard microdilution method. The interaction intensity was determined by spectrophotometry for the chequerboard assay, and the nature of the interactions was assessed using two non-parametric approaches [fractional inhibitory concentration index (FICI) and DeltaE models]. The interaction between THY-FLC or THY-AMB in FLC-resistant and -susceptible strains of C. albicans showed a high percentage of synergism by the FICI method and the DeltaE method. The DeltaE model gave results consistent with FICI, and no antagonistic action was observed in the strains tested.

Abstract We analyzed 40 year data sets of daily average visibility (a proxy for surface aerosol concentration) and hourly precipitation at seven weather stations, including three stations located on the Taihang Mountains, during the summertime in northern China. There was no significant trend in summertime total precipitation at almost all stations. However, light rain decreased, whereas heavy rain increased as visibility decreased over the period studied. The decrease in light rain was seen in both orographic‐forced shallow clouds and mesoscale stratiform clouds. The consistent trends in observed changes in visibility, precipitation, and orographic factor appear to be a testimony to the effects of aerosols. The potential impact of large‐scale environmental factors, such as precipitable water, convective available potential energy, and vertical wind shear, on precipitation was investigated. No direct links were found. To validate our observational hypothesis about aerosol effects, Weather Research and Forecasting model simulations with spectral‐bin microphysics at the cloud‐resolving scale were conducted. Model results confirmed the role of aerosol indirect effects in reducing the light rain amount and frequency in the mountainous area for both orographic‐forced shallow clouds and mesoscale stratiform clouds and in eliciting a different response in the neighboring plains. The opposite response of light rain to the increase in pollution when there is no terrain included in the model suggests that orography is likely a significant factor contributing to the opposite trends in light rain seen in mountainous and plain areas.

Abstract Arctic climate changes include not only changes in trends and mean states but also strong interannual variations in various fields. Although it is known that tropical-extratropical teleconnection is sensitive to changes in flavours of El Niño, whether Arctic climate variability is linked to El Niño, in particular on interannual timescale, remains unclear. Here we demonstrate for the first time a long-range linkage between central Pacific (CP) El Niño and summer Arctic climate. Observations show that the CP warming related to CP El Niño events deepens the tropospheric Arctic polar vortex and strengthens the circumpolar westerly wind, thereby contributing to inhibiting summer Arctic warming and sea-ice melting. Atmospheric model experiments can generally capture the observed responses of Arctic circulation and robust surface cooling to CP El Niño forcing. We suggest that identification of the equator-Arctic teleconnection, via the ‘atmospheric bridge’, can potentially contribute to improving the skill of predicting Arctic climate.

The National Centers for Environmental Prediction (NCEP) Climate Forecast System (CFS) provides important source of information on seasonal climate prediction for many Asian countries that are affected by monsoon. In this study, the authors provide a comprehensive assessment of the prediction of East Asian winter monsoon (EAWM) by the CFS version 2 (CFSv2) using the hindcast for 1983–2010, with a focus on seasonal–interannual time scales. Output from the Atmospheric Model Intercomparison Project (AMIP) and the Coupled Model Intercomparison Project (CMIP) simulations is also analyzed to understand the physical process of monsoon. Several major features of the EAWM are well predicted by the CFSv2. Particularly, the EAWM‐related atmospheric circulation and surface climate over oceans are well predicted several months in advance, and the prediction over oceans is better than that over land. While the CFSv2 has low skill in predicting the Arctic Oscillation (AO), it well predicts El Niño‐Southern Oscillation (ENSO) and its impact on the EAWM, contributing to the decent prediction of EAWM. Comparisons among hindcast, AMIP, and CMIP indicate that ocean–atmosphere coupling is important for EAWM prediction. While the EAWM in AMIP is weaker, CMIP predicts more realistic monsoon features. The enhanced performance of CMIP is partly attributed to its better simulation of precipitation over the western Maritime Continent (MC). All three types of experiments fail to depict the relationship between EAWM and AO and simulate a stronger‐than‐observed response of EAWM to ENSO. Improving the simulation of convection over the MC potentially enhances the skill of CFSv2 in predicting the EAWM.

Based on the satellite data from the Climate Prediction Center morphing (CMORPH) at very high spatial and temporal resolution, the effects of urbanization on precipitation were assessed over the Pearl River Delta (PRD) metropolitan regions of China. CMORPH data well estimates the precipitation features over the PRD. Compared to the surrounding rural areas, the PRD urban areas experience fewer and shorter precipitation events with a lower precipitation frequency (ratio of rainy hours, about 3 days per year less); however, short-duration heavy rain events play a more significant role over the PRD urban areas. Afternoon precipitation is much more pronounced over the PRD urban areas than the surrounding rural areas, which is probably because of the increase in short-duration heavy rain over urban areas.

Abstract A study was conducted to determine the pattern of light interception and distribution in a field soybean community. Light interception occurred primarily at the periphery of the canopy. When the open space between rows closed or when it was nearly closed, interception was primarily at the top of the canopy. The distribution of light through a soybean community could be approximated by an exponential distribution. The slope of the regression of the logarithm of percent light interception of leaf area index (LAI) above the point of light measurement was affected by the morphology of the community. From the distribution of percent light and cumulative LAI, an estimate of the “effective” LAI was determined. The large amount of self‐shading and predominant interception at the periphery of the canopy indicates that many lower leaves are not receiving adequate radiation. An increase in yield could possibly be achieved by selecting varieties whose natural inclination leads to deeper penetration of useful energy to a greater number of leaves.

Rice plant counting is crucial for many applications in rice production, such as yield estimation, growth diagnosis, disaster loss assessment, etc. Currently, rice counting still heavily relies on tedious and time-consuming manual operation. To alleviate the workload of rice counting, we employed an UAV (unmanned aerial vehicle) to collect the RGB images of the paddy field. Then, we proposed a new rice plant counting, locating, and sizing method (RiceNet), which consists of one feature extractor frontend and 3 feature decoder modules, namely, density map estimator, plant location detector, and plant size estimator. In RiceNet, rice plant attention mechanism and positive-negative loss are designed to improve the ability to distinguish plants from background and the quality of the estimated density maps. To verify the validity of our method, we propose a new UAV-based rice counting dataset, which contains 355 images and 257,793 manual labeled points. Experiment results show that the mean absolute error and root mean square error of the proposed RiceNet are 8.6 and 11.2, respectively. Moreover, we validated the performance of our method with two other popular crop datasets. On these three datasets, our method significantly outperforms state-of-the-art methods. Results suggest that RiceNet can accurately and efficiently estimate the number of rice plants and replace the traditional manual method.

BACKGROUND: Food safety is an important worldwide public health concern, and microbial contamination in foods not only leads to food deterioration and shelf life reduction but also results in economic losses and disease. OBJECTIVE: The main aim of the present study was to evaluate the effect of epsilon-poly-L-lysine (ε-PL) and citral combination against Escherichia coli O157:H7 (E. coli O157:H7) strains. The preliminary antioxidant and antitumor activities were also studied. DESIGN: Synergism is a positive interaction created when two compounds combine and exert an inhibitory effect that is greater than the sum of their individual effects. The synergistic antimicrobial effect of ε-PL and citral was studied using the checkerboard method against E. coli O157:H7. The minimal inhibitory concentration, time-kill, and scanning electron microscope assays were used to determine the antimicrobial activity of ε-PL and citral alone or in combination; 2,2-diphenyl-1-picrylhydrazyl-scavenging assay and western blotting were used in antioxidant activity assays; cell viability assay was carried out to finish preliminary antitumor test. RESULTS: Minimal inhibitory concentrations of ε-PL and citral resisted to the five E. coli O157:H7 strains were 2-4 µg/mL and 0.5-1 µg/mL, and the fractional inhibitory concentration indices were 0.25-0.375. The results of time-kill assay revealed that a stronger bactericidal effect in a laboratory medium might be exerted in the combination against E. coli O157:H7 than that in a food model. The compounds alone or in combination exhibited a potential 2,2-diphenyl-1-picrylhydrazyl radical-scavenging activity, and the expression of superoxide dismutase 1 and glutathione peroxidase 1 protein increased. The preliminary antitumor activity effect of the combination was better than ε-PL or citral alone. CONCLUSIONS: These findings indicated that the combination of ε-PL and citral could not only be used as a promising naturally sourced food preservative but also be used in the pharmaceutical industry.

Abstract By using winter (December–February) daily temperature at 1629 meteorological stations over China during 1960/61‐2017/18, spatial–temporal changes and probability distribution characteristics of winter temperature and extreme cold events in China were analysed, with a special emphasis on the warming hiatus in China. The results are as follows: (1) the winter temperature in China showed an overall upward trend during the past six decades. However, since the winter of 2006 (so‐called the warming hiatus period), the winter temperature in China has remained stable and even decreased slightly. (2) There is an obvious difference in winter temperature between South China and North China. North China witnessed a more obvious temperature rise during the warm period (1986–2005) than South China did. However, since 2006, winter temperature in most parts of North China has dropped slightly, with a marked increase in extreme cold events. In contrast, South China did not undergo an obvious temperature drop during the hiatus period. (3) The range of temperature change in North China is larger than that in South China. The range of minimum temperature is also wider than that of maximum temperature, with a noticeable increase in extreme low temperature events since 2006. In such situation, North China is more likely to encounter extreme low temperature events, such as cold wave and low temperature weather. (4) China has experienced an increase in extreme cold events during the hiatus period. There is an obvious upward trend in regional long‐lasting extreme cold events (3–5 and 11–20 days duration). Consequently, this study has revealed that winter temperature and frequency of extreme cold events in China was not only influenced by global warming, with a persistent warming, but also showed an obvious inter‐decadal variation which is associated with the natural forcing. It indicates that the natural forcing factor is also a main factor influencing and modulating the winter temperature change at the inter‐decadal scale at the regional scale as China even in the era of the global warming caused by anthropogenic forcing.

Graphene oxide (GO)/graphene (GN) nanosheets were coated onto the poly(glycidyl methacrylate-ethylene dimethacrylate) monolithic bed synthesized inside the capillary in order to prepare a promising polymer monolith microextraction (PMME) material (GO/GN@poly(GMA-EDMA)). Various techniques, including Fourier transform infrared spectroscopy, atomic force microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy, were employed to characterize the synthesized GO/GN@poly(GMA-EDMA) monoliths, confirming that GO/GN was effectively functionalized on the poly(GMA-EDMA) monolithic materials. Furthermore, a new method was developed for the analysis of sarcosine (identified as a potential prostate cancer biomarker) using PMME coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS). Under the preoptimized conditions, the monolithic column afforded satisfactory enhancement factor (32-fold) and low limits of detection (1.0 ng mL(-1)) were obtained. In comparison to several other commercialized solid phase extraction adsorbents, GN@poly(GMA-EDMA) monoliths exhibited excellent performance with recoveries of sarcosine approaching 93% with relative standard deviations less than 11.5%.