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Polyaromatic hydrocarbons (PAHs) are ubiquitous in the environment and food. The Joint FAO/WHO Expert Committee on Food Additives concluded 13 individual PAHs are carcinogenic and genotoxic in vitro and in vivo. Food is recognized as the main source of exposure to PAHs for adult non-smokers, which contributed to more than 90% of total exposure. In this study, 300 food samples were collected in Hong Kong, analysed the levels of 16 European Union priority PAHs, the dietary exposure to these PAHs by the local adult population from these food items, and the associated health risk. The most predominant detectable PAH was chrysene (CHR) (14.4%), followed by benzo[c]fluorene (11.2%), benzo[a]anthracene (BaA) (10.6%) and benzo[b]fluoranthene (BbFA) (7.8%). The dietary exposures for average consumers of benzo[a]pyrene (BaP) and PAH4 (sum of BaP, CHR, BaA and BbFA) were 0.13–0.90 and 1.4–4.2 ng/kg bw/day respectively for lower and upper bound approaches. Cereal and its products contributed more than 50% to BaP and PAH4 for average consumers in a lower-bound approach. The margin of exposure (MOE) approach was used to assess the health risks of consumers. The calculated MOE values for both BaP and PAH4 of the average and high consumers (90th percentile) were >50,000, indicating a low concern for the health of the Hong Kong population. [ABSTRACT FROM AUTHOR]

Sterigmatocystin (STC) is a toxic and potentially carcinogenic fungal toxin found in a variety of food commodities. This study describes the development of an analytical method to determine STC in roasted coffee beans and black pepper using ultra performance liquid chromatography (UPLC) coupled with triple quadrupole tandem mass spectrometry (MS/MS). 13C18-STC was used as internal standard. STC was extracted with a mixture of acetonitrile/water, diluted with a buffer, followed by purification with a solid-phase extraction and an immunoaffinity column prior to the UPLC-MS/MS analysis. Two multiple reaction monitoring (MRM) transitions were employed, one for quantification and one for confirmation of STC. The UPLC-MS/MS analytical method was validated with respect to selectivity, linearity, sensitivity, accuracy, precision, recovery, and stability. Calibration curves were linear over a concentration range 25–2,500 pg mL−1 with correlation coefficients (r) > 0.998. The method limit of quantification for STC in roasted coffee beans and black pepper was 0.10 μg kg−1. The accuracy and precision of the analytical method were acceptable within 15% at all quality control levels. This method was suitable to determine STC levels because of its selectivity, precision, and accuracy. The method was successfully applied to roasted coffee beans and black pepper samples. [ABSTRACT FROM AUTHOR]

Abstract: Nowadays, the use of pesticides is inevitable for pest control in crops, especially for fruit and vegetables. After the harvest from raw agricultural commodities, the amount of pesticide residues in food is mainly influenced by the storage, handling and processing that follow. If good agricultural and good manufacturing practices are enforced effectively, the amount of pesticide residues would be brought below the corresponding maximum residue level. Thus, the consumption of raw and/or prepared fruit and vegetables would be safe. Nonetheless, reports regarding pesticide residues in fruit or vegetables on mass media have been worrying consumers, who are concerned about the adverse effects of pesticide residues. As a result, consumers perform household processing before consumption to reduce any related risks. However, can these preparations effectively remove pesticide residues? Reviewing the extensive literature, it showed that, in most cases, washing and soaking can only lead to a certain degree of reduction in residue level, while other processing such as peeling, soaking in chemical baths and blanching can reduce pesticide residues more effectively. In general, the behaviour of residues during processing can be rationalised in terms of the physico‐chemical properties of the pesticide and the nature of the process. In contrast, the reported studies are diversified and some areas still lack sufficient studies to draw any remarks. Recommendations are provided with respect to the available information that aims to formulate an environmental friendly, cost‐effective and efficient household processing of fruit and vegetables to reduce pesticide residues. © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Cereals and feed contaminated with ergot alkaloids (EAs) have been of concern for several decades. Nowadays, analysis of EAs is focused on ergometrine, ergotamine, ergosine, ergocristine, ergocryptine (a mixture of α- and β-isomers) and ergocornine and their related -inine epimers as listed in the European Commission Recommendation 2012/154/EU. Liquid chromatography with fluorescence detection has been used for quantification of EAs for decades whilst LC-MS has become the work-horse for quantification of EAs in the last decade. However, in LC-MS analysis matrix effects of different magnitudes exist for each EA epimer, especially ergometrine/ergometrinine, even after different clean-up procedures. This leads to an underestimation or overestimation of EAs levels. Moreover, isotopic labelled standards for EAs are still not available in the market. This review aims to provide background information on different analytical methods, discuss their advantages and disadvantages and possible advancement. Moreover, the method performance requirements to support forthcoming regulations are also discussed.

4-Nonylphenol (4-NP) is a para-substituted phenolic compound comprising a straight or branched carbon chain group while branched 4-NP consists of 211 possible structural isomers. NP is recognised as an environmental pollutant and exists ubiquitously in both the environment and in food. 4-NP, especially branched 4-NP, has been shown to have the potential role of endocrine disruptor and xeno-oestrogen. Moreover, different NP isomers also exhibit different oestrogen-like activities. Recently, it was reported that the isomer-specific profile of 4-NP in foodstuffs varies greatly between and within food groups. Hence, risk assessment based on total branched 4-NP cannot reflect dietary risk. This study reviews the analytical methods applicable to conduct an isomer-specific analysis of 4-NP and its occurrence in foodstuffs. Lastly, research gaps are identified for future research.

The degree of organotin compounds (OTCs), including dibutyltin, tributyltin, triphenyltin and dioctyltin, contamination in seafood purchased in 2017 and 2018 from Hong Kong market was studied. Edible portions of 341 seafood samples, including fish, crustaceans and molluscs, were used for analysis by gas chromatograph coupled to an inductively coupled plasma mass spectrometry (GC-ICP/MS). The method detection limits and quantification limits of OTCs were below or equal to 0.25 and 1.0 μg Sn kg -1 respectively. Triphenyltin accounted for the majority amongst other OTCs and was detected in 53% of samples. In general, mean total OTCs levels of fish (24 μg Sn kg -1 ) were higher than crustaceans (14 μg Sn kg -1 ) and molluscs (15 μg Sn kg -1 ). The highest detected levels of triphenyltin, tributyltin, dibutyltin and dioctyltin were found to be 480, 24, 4.5 and 0.89 μg Sn kg -1 in a mangrove snapper, noodle fish, coral clam and giant grouper respectively., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Tributyltin and triphenyltin have been extensively applied in anti-fouling paints since the 1960s. Hence, organotin compounds (OTCs), especially butyltins and phenyltins, in seafood has been of concern for decades. Even though the "International Convention on the Control of Harmful Anti-Fouling Systems on Ships, 2001" entered into force internationally in 2008 and prohibited the use of OTCs in anti-fouling paints used on ships, the analysis of OTCs in seafood was not commonly included in routine monitoring programmes. Besides, species of triphenyltin, including triphenyltin hydroxide and acetate, have been used as pesticides and may accumulate in food. Moreover, the European Food Safety Agency established a group tolerable daily intake for tributyltin, dibutyltin, triphenyltin and dioctyltin in 2004 as they exert their immunotoxic effects by similar mode of action and potency. Therefore, suitable methods are needed to analyze butyl-, phenyl- and octyl-tins simultaneously in food without affecting their moieties. This review aims to provide background information in this area., (Copyright © 2017 Elsevier B.V. All rights reserved.)

The use of pesticides and other chemicals has become a common practice in modern agriculture to enhance and stabilise crop yield, protect the nutritional integrity of food, facilitate food storage to assure year-round supplies, and provide attractive and appealing food products. With the adoption of strict good agricultural practice (GAP), only minimal amounts of pesticide residues should remain on the crops or in connected foods of animal origin up the food chain. To assess their associated health risk to local people, the dietary exposure of Hong Kong adults to residues of four groups of pesticides or their metabolites - organophosphorus pesticides (OPPs), carbamates, pyrethrins and pyrethroids, and dithiocarbamate (DTC) metabolites - is estimated in the first Hong Kong Total Diet Study (TDS). A total of 150 commonly consumed food items were collected and prepared "as consumed". A total of 600 composite food samples were analysed for 85 pesticides or their metabolites by liquid chromatography-tandem mass spectrometry (LC-MS/MS). These pesticides were primarily found at low levels (highest mean = 350 μg kg⁻¹) in food samples of plant origin such as vegetables and fruits. Dietary exposures to pesticide residues were estimated based on the analytical results and the food consumption data of the local residents. The estimated dietary exposures of Hong Kong adults to all individual pesticides were well below their respective acceptable daily intakes (ADIs). The percentage contributions of the estimated mean and 95th percentile dietary exposures to the ADIs of individual pesticides were <6% and <24% for the OPPs, <1% for the carbamates and pyrethrins and pyrethroids, and <1% and <4% for the DTC metabolites, respectively. The findings indicate that dietary exposures to all the pesticide residues analysed in this study were unlikely to pose unacceptable health risks to the Hong Kong population.

Acrylamide is a processing contaminant in food formed during cooking at high temperature, such as frying and baking. To assess the associated health risk of the Hong Kong population, the dietary exposure of Hong Kong adults to acrylamide was estimated in the first Hong Kong Total Diet Study (TDS), where food samples were collected and prepared "as consumed". A total of 532 composite food samples were analysed for acrylamide using LC-MS/MS. Dietary exposures were estimated by combining the analytical results with the food consumption data of the Hong Kong adults. The mean and 95th percentile exposures to acrylamide of the Hong Kong population were 0.213 and 0.538 μg kg⁻¹ body weight (bw) day⁻¹, respectively, and their margins of exposure (MOEs) were all below 10,000. The main dietary source of acrylamide was "Vegetables and their products" (52.4% of the total exposure), particularly stir-fried vegetables (44.9%), followed by "Cereals and their products" (14.7%) and "Mixed dishes" (9.43%). The study findings suggest that the relatively low figures for MOE for a genotoxic carcinogen may indicate human health concern of the Hong Kong population. Efforts should continue to be made in the interest of reducing acrylamide levels in food locally.

A total of 290 individual food samples were collected in Hong Kong, China, for 3-monochloropropane-1,2-diol (3-MCPD) fatty acid esters analysis. Most samples were processed food and in ready-to-eat form. The results show that the levels of 3-MCPD fatty acid esters were high in biscuits, fats and oils, snacks and Chinese pastry with mean bound 3-MCPD levels of 440, 390, 270 and 270 μg kg⁻¹, respectively. The dietary exposures to bound 3-MCPD of average and high adult consumers were estimated to be 0.20 and 0.53 μg kg bw⁻¹ day⁻¹, respectively. The primary toxicological concern of 3-MCPD fatty acid esters is its potential to release 3-MCPD in vivo during digestion in the gastrointestinal tract. 3-MCPD would affect the kidney, the central nervous system and the male reproductive system of rats. Assuming that 100% of the 3-MCPD was released from 3-MCPD fatty acid esters by hydrolysis in the digestive system, the dietary exposures to 3-MCPD for average and high adult consumers were only 10% and 26% of the provisional maximum tolerable daily intake (PMTDI) of 3-MCPD established by the Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives (JECFA) (2 μg kg bw⁻¹ day⁻¹), respectively. The results suggest that both average and high adult consumers are unlikely to experience major toxicological effects of 3-MCPD.

The aim of this study was to determine the level of bound 3-monochloropropan-1,2-diol in foodstuffs commonly consumed in Hong Kong, China, by an enzymatic hydrolysis indirect method which proved to be free from interferences. A total of 290 samples were picked up randomly from the local market and analysed. About 73% of these samples were found to contain detectable amounts of bound 3-MCPD. Amongst the 73 food items, bound 3-MCPD was not detected in 13 food items, including extra virgin olive oil, beef ball/salami, beef flank, ham/Chinese ham, nuts, seeds, soy sauce, oyster sauce, butter, yoghurt, cream, cheese and milk. For those found to contain detectable bound 3-MCPD, the content ranged up to 2500 µg kg(-1). The highest mean bound 3-MCPD content among the 14 food groups was in biscuits (440 [50-860] µg kg(-1)), followed by fats and oils (390 [n.d.-2500] µg kg(-1)), snacks (270 [9-1000] µg kg(-1)), and Chinese pastry (270 [n.d.-1200] µg kg(-1)). Among the samples, the highest bound 3-MCPD content was in a grape seed oil (2500 µg kg(-1)), followed by a walnut flaky pastry (1200 µg kg(-1)) and a grilled corn (1000 µg kg(-1)). Basically, the results of this study agreed well with other published results in peer-reviewed journals, except for cheese, cream, ham, nuts and seeds.

Inorganic arsenic, a human carcinogen, can be found in the environment and food. In the first Hong Kong Total Diet Study, the dietary exposure of the Hong Kong people, including various age-gender subgroups, to inorganic arsenic was estimated for assessing the associated health risk. Food samples, which represented the Hong Kong people's diet, were collected and prepared "as consumed" for analysis. Concentrations of inorganic arsenic, as sum of arsenite (As(III)) and arsenate (As(V)) were determined in 600 composite samples by using inductively coupled plasma mass spectrometry. The dietary exposures were estimated by combining the analytical results with the local food consumption data of the adult population. The mean and 95th percentile of inorganic arsenic exposures of the Hong Kong people were 0.22 and 0.38μg/kg body weight (bw)/day, respectively. Among the 12 age-gender subgroups, the respective exposures ranged from 0.19 to 0.26μg/kg bw/day and from 0.33 to 0.46μg/kg bw/day. The main food category that contributed inorganic arsenic was "cereals and their products" (53.5% of the total exposure), particularly rice. Having considered the carcinogenic risk of inorganic arsenic to humans, it is suggested that efforts should be made to reduce the inorganic arsenic exposure of the Hong Kong population., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Organochlorine pesticide (OCP) residues in foods have been of concern for several decades. However, the analysis of some of the OCPs and their metabolites or derivatives, such as endrin aldehyde, endrin ketone, nonachlor, etc. in fatty foods (including foods of animal and plant origin), was not commonly included in routine monitoring programme. Recently, the Stockholm Convention introduced nine plus one new persistent organic pollutants (POPs) that included chlordecone and some other OCPs. Is there a method available that can analyze both traditional OCPs, together with their metabolites and derivatives in fatty foods? Furthermore, is there a suitable method that can monitor OCPs and the newly added POPs including chlordecone in fatty foods together in a pot? This review aims to provide some background information to answer these questions., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Levels of nitrate and nitrite in 73 different vegetables, a total of 708 individual samples grouped into leafy, legumes, root and tuber, and fruiting vegetables, which are traded mainly in Hong Kong, were measured. Where available, five samples of each vegetable type were purchased from different commercial outlets during the winter of 2008 and summer of 2009. Levels of nitrate and nitrite were determined by ion chromatography and flow injection analysis, respectively. Nitrate and nitrite levels of all samples ranged <4-6300 and <0.8-9.0 mg kg⁻¹, respectively. Nitrate concentrations for the different groups, in descending order, were leafy > root and tuber > fruiting and legume vegetables. More than 80% of vegetables had mean nitrate concentrations less than 2000 mg kg⁻¹, but mean nitrate concentrations of three types of leafy vegetables, namely Chinese spinach, Shanghai cabbage and Chinese white cabbage, were >3500 mg kg⁻¹. On the other hand, nitrite concentrations were generally low - <1 mg kg⁻¹ on average. Nitrate in vegetables (i.e. Chinese flowering cabbage, Chinese spinach and celery) can be reduced significantly (12-31%) after blanching for 1-3 min, but not after soaking.

This paper reports a comprehensive sensitive multi-residue liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for detection, identification and quantitation of 73 pesticides and their related products, a total of 98 analytes, belonging to organophosphorus pesticides (OPPs) and carbamates, in foods. The proposed method makes use of a modified QuEChERS (quick, easy, cheap, effective, rigged, and safe) procedure that combines isolation of the pesticides and sample clean-up in a single step. Analysis is performed by liquid chromatography-electrospray ionization-tandem mass spectrometry operated in the multiple reaction monitoring (MRM) mode, acquiring two specific precursor-product ion transitions per target compound. Two main fragment ions for each pesticide were obtained to achieve the identification according to the SANCO guidelines 10684/2009. The method was validated with various food samples, including edible oil, meat, egg, cheese, chocolate, coffee, rice, tree nuts, citric fruits, vegetables, etc. No significant matrix effect was observed for tested pesticides, therefore, matrix-matched calibration was not necessary. Calibration curves were linear and covered from 1 to 20 microg L(-1) for all compounds studied. The average recoveries, measured at 10 microg kg(-1), were in the range 70-120% for all of the compounds tested with relative standard deviations below 20%, while a value of 10 microg kg(-1) has been established as the method limit of quantitation (MLOQ) for all target analytes. Similar trueness and precision results were also obtained for spiking at 200 microg kg(-1). Expanded uncertainty values were in the range 21-27% while the HorRat ratios were below 1. The method has been successfully applied to the analysis of 700 food samples in the course of a baseline monitoring study of OPPs and carbamates., (2010 Elsevier B.V. All rights reserved.)

A total of 256 individual food samples were collected in Hong Kong for aluminium testing. Most of food samples were analysed in ready-to-eat form. High aluminium levels were found in steamed bread/bun/cake (mean: 100-320 mg kg(-1)), some bakery products such as muffin, pancake/waffle, coconut tart and cake (mean: 250, 160, 120 and 91 mg kg(-1), respectively), and jellyfish (ready-to-eat form) (mean: 1200 mg kg(-1)). The results demonstrated that aluminium-containing food additives have been widely used in these food products. The average dietary exposure to aluminium for a 60 kg adult was estimated to be 0.60 mg kg(-1) bw week(-1), which amounted to 60% of the new PTWI established by JECFA. The main dietary source was "steamed bread/bun/cake", which contributed to 60% of the total exposure, followed by "bakery products" and "jellyfish", which contributed to 23 and 10% of the total exposure, respectively. However, the estimation did not include the intake of aluminium from natural food sources, food contact materials or other sources (e.g. drinking water). Although the results indicated that aluminium it is unlikely to cause adverse health effect for the general population, the risk to some populations who regularly consume foods with aluminium-containing food additives cannot be ruled out.

The aim of this study was to determine the dietary exposure of DDT in foodstuffs consumed in Hong Kong by secondary school students in Hong Kong in 2005. Food samples of domestic or imported food were collected randomly from local markets for the determination of DDT. The analytical method for this survey was based on isotope dilution technique. DDT isomers were determined at parts per billion (microg kg(-1)) levels in foods by pressured fluid extraction followed by gel permeation column cleanup and gas chromatography with mass spectrometry detection. Among the 98 composite samples, 25 were found positive with DDT levels greater than the limit of quantitation (LOQ) (1 microg kg(-1) for each isomer of DDT). Only two of the meat products were found to contain low levels of the metabolites of DDT. A number of fish and shellfish were found to contain not just the metabolites of DDT, but also parent DDT. The main contribution to DDT was from seafood. The dietary intake of DDT for an average and high secondary school student consumers were estimated to be 0.145 and 0.291 microg kg(-1) bwd(-1), respectively. Both levels fell well below the Provisional Tolerable Daily Intake (PTDI) of 10 microg kg(-1) bwd(-1) established by the Joint Food Agriculture Organization/World Health Organization Meeting on Pesticide Residues (JMPR). It was concluded that both the average and high secondary school student consumers were unlikely to experience major toxicological effects of DDT.

Ochratoxin A (OTA) is a toxic and potentially carcinogenic fungal toxin found in a variety of food commodities. A new sensitive method has been developed to quantify OTA in cereal products by reversed-phase liquid chromatography (LC) with mass spectrometric (MS) detection. Ochratoxin B was used as the internal standard. OTA was extracted from cereal products with acetonitrile-water, and the extract was diluted with a buffer; the diluted extract was cleaned up on an immunoaffinity column before LC/MS analysis. Two multiple-reaction monitoring transitions were used, one for quantification of OTA and one for confirmation of identity. The method was shown to be highly sensitive, with a low decision limit (CCalpha) of 0.012 microg/kg and a detection capability (CCbeta) of 0.021 microg/kg. Within-laboratory repeatability coefficient of variation values were 7.1, 3.7, and 3.1%, and the corresponding recoveries were 104, 106, and 103% for rice samples fortified with OTA at 0.05, 0.10, and 0.15 microg/kg, respectively. Method validation was performed according to the criteria of European Commission Decision 2002/657/EC. All criteria as presented in the Commission Decision were fulfilled. This method is the first fully validated method using immunoaffinity chromatography for cleanup and MS for detection in the analysis of cereals for OTA. The method was also successfully applied to cereal-derived products. The analytical results for determination of the OTA content of cereal products commercially available in Hong Kong are also reported.