Miniaturised sample preparation method for the multiresidual determination of regulated organohalogenated pollutants and related compounds in wild bird eggs.

A simplified, miniaturised matrix solid-phase dispersion (MSPD)-based method allowing the simultaneous extraction and purification of contaminants belonging to selected families of regulated persistent organic pollutants (POPs), i.e. polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and penta- to octa-polybrominated diphenyl ethers (PBDEs), and related contaminants of emerging concern, such as deca-BDE and Dechlorane Plus (DP), has been proposed. Wild bird eggs were used as biotic fat-containing model matrices. Once optimised, the procedure allowed sample preparation to be accomplished within 30 min, in a single step, and with minimal sample and reagent consumption and waste generation. These features contributed to speeding up and greening the analytical process as compared to the large-scale multistep procedures for these types of analyses. The method was combined with gas chromatography-quadrupole mass spectrometry (GC-qMS) for PCB and OCP analysis and with GC-negative ion chemical ionisation-quadrupole mass spectrometry (NCI-qMS) for PBDE and DP determination. The complete analytical method provided satisfactory recoveries of the target compounds (above 83% for all analytes, except for PBDE 209, 63%), although as small an amount of sample as 0.300 g was used. The repeatability of the complete procedure was less than 16% (with the only exception for PCB 153, which looked to be affected by an interference). The limits of detection were in all cases lower than 34 pg g-1 dry weight (as calculated for real samples), demonstrating the feasibility of the proposed procedure for accurate determination of the target compounds in biological samples. The proposed procedure was applied to the analysis of the target POPs in unhatched eggs of wild bird species. Graphical abstract Scheme of the miniaturised methodology proposed for environmental monitoring of POPs and related compounds in wild bird eggs.

Field evaluation of a dual rapid diagnostic test for HIV infection and syphilis in Lima, Peru.

OBJECTIVES: Screening for HIV and syphilis in key populations is recommended by the WHO to reduce the morbidity, mortality and transmission associated with undiagnosed and untreated infections. Rapid point-of-care tests that can detect multiple infections with a single fingerprick whole blood specimen using a single device are gaining popularity. We evaluated the field performance of a rapid dual HIV and syphilis test in people at high risk of HIV and syphilis infections. METHODS: Participants included men who have sex with men and transgender women recruited in Lima, Peru. Reference standard testing for detection of HIV and syphilis infections, conducted using blood samples from venipuncture, included Treponema pallidum particle agglutination and fourth-generation HIV enzyme immunoassay for which positive results had a confirmation HIV Western blot test. For the evaluation test, SD BIOLINE HIV/Syphilis Duo test (Standard Diagnostics, Korea), a fingerprick blood specimen was used. Sensitivity and specificity were calculated and the exact binomial method was used to determine 95% CIs. RESULTS: A total of 415 participants were recruited for the study. The dual test sensitivity for detection of T. pallidum infection was 89.2% (95% CI 83.5% to 93.5%) and specificity 98.8% (95% CI 96.5% to 99.8%). For detection of HIV infection, the sensitivity of the dual test was 99.1% (95% CI 94.8% to 100%) and specificity 99.4% (95% CI 97.7% to 99.9%). CONCLUSIONS: This high performing dual test should be considered for the use in clinical settings to increase uptake of simultaneous testing of HIV and syphilis and accelerate time to treatment for those who need it.

Field Evaluation of a Dual Rapid Immunodiagnostic Test for HIV and Syphilis Infection in Peru.

BACKGROUND: Integrated prevention for HIV and syphilis is warranted because both syphilis and HIV infections have evidence-based, scalable interventions using current health care mechanisms. The advent of dual rapid point-of-care tests, single devices that can detect multiple infections using the same specimen, provides the opportunity to integrate the screening of syphilis into HIV prevention programs, potentially increasing the numbers of people tested and allowing for same-day testing and treatment. The aim of our study was to evaluate the MedMira Multiplo Rapid TP/HIV Antibody Test (MedMira Inc, Halifax, Nova Scotia, Canada), a qualitative, rapid immunoassay that detects antibodies to Treponema pallidum and HIV. METHODS: The reference test for comparison to the T. pallidum component of the Multiplo TP/HIV Test was the T. pallidum particle agglutination assay. For the HIV component, the reference test included a fourth-generation enzyme immunoassay with a confirmatory Western blot test. RESULTS: The sensitivity and specificity for the HIV antibody component were 93.8% (95% confidence interval [CI], 69.8%-99.8%) and 100% (95% CI, 97.7%-100%), respectively. The T. pallidum component of the test had a sensitivity of 81.0% (95% CI, 68.1%-94.6%) and a specificity of 100% (95% CI, 97.6%-100%). CONCLUSIONS: Our study showed excellent performance of the HIV antibody component of the test and very good performance for the T. pallidum antibody component of the MedMira Multiplo Rapid TP/HIV Antibody Test, which should be considered to improve screening coverage. Use of effective dual tests will create improved access to more comprehensive care by integrating the screening of syphilis into HIV prevention programs.

Treponema pallidum pallidum Genotypes and Macrolide Resistance Status in Syphilitic Lesions among Patients at 2 Sexually Transmitted Infection Clinics in Lima, Peru.

We report the circulating genotypes and the frequency of macrolide-resistance patterns among Treponema pallidum pallidum DNA isolated from syphilitic lesions from patients who attended 2 sexual health clinics in Lima, Peru. We implemented and used a molecular typing scheme to describe local T. pallidum pallidum strains. Among 14 specimens, subtype 14d/f was the most prevalent strain in 7 fully typed T. pallidum DNA specimens obtained from men who have sex with men and transgender women presenting with chancre-like lesions. No macrolide-resistance mutations were found in T. pallidum DNA from 10 lesions.

Laboratory evaluation of a dual rapid immunodiagnostic test for HIV and syphilis infection.

New dual tests for HIV and syphilis have been developed. Our study aimed to evaluate the laboratory performance of a dual rapid immunodiagnostic test for HIV and syphilis. Our evaluation showed high performance of this dual rapid test, which should be considered for implementation to increase screening coverage and efficiency.

Programmatic implementation of depression screening and remote mental health support sessions for persons recently diagnosed with TB in Lima, Peru during the COVID-19 pandemic.

Background: Few studies have explored a stepped care model for delivering mental health care to persons with tuberculosis (TB). Here, we evaluated depression screening and remote low-intensity mental health interventions for persons initiating TB treatment in Lima, Peru during the COVID-19 pandemic. Methods: We used the Patient Health Questionnaire 9 (PHQ-9) to screen participants for depressive symptoms (PHQ-9 ≥ 5). Participants with PHQ-9, 5-14 received remote Psychological First Aid (PFA) or Problem Management Plus (PM+). Participants were reevaluated 6 months after intervention completion. We then compared the change in median PHQ-9 scores before and after intervention completion. Those with PHQ-9 ≥ 15 were referred to higher-level care. Findings: We found that 62 (45.9%) of the 135 participants had PHQ-9 ≥ 5 at baseline. Then, 54 individuals with PHQ-9, 5-9 received PFA, of which 44 (81.5%) were reevaluated. We observed significant reductions in median PHQ-9 scores from 6 to 2 (r = 0.98; p < 0.001). Four participants with PHQ-9, 10-14 received PM+ but were unable to be reevaluated. Four participants with PHQ-9 ≥ 15 were referred to higher-level care. Conclusions: Depressive symptoms were common among persons recently diagnosed with TB. We observed improvements in depressive symptoms 6 months later for most participants who received remote sessions of PFA.

Optimisation of a biotechnological procedure for selective fractionation of bioactive inositols in edible legume extracts.

BACKGROUND: Currently, disorders such as diabetes mellitus, obesity or atherosclerosis are recognised as major global health problems. The use of inositols for treating these illnesses has attracted considerable attention and their extraction from natural sources presents added value as they are considered bioactive ingredients in the food industry. Legumes are natural and rich sources of inositols; however, the co-existence of other low molecular weight carbohydrates (LMWCs) in their extracts, which interfere in their bioactivity, might constitute an important drawback, thereby making their removal essential. RESULTS: LMWCs, including inositols, methyl-inositols and glycosyl-inositols of different legume extracts, were determined by GC-MS; the presence of bornesitol (2.35 mg g(-1) ) and lathyritol (0.27 mg g(-1) ) were reported for the first time in grass peas. The use of Saccharomyces cerevisiae for the selective removal of interfering carbohydrates was optimised. Incubation time (3-40 h) was highly dependent on the composition of the legume considered; inositol contents were generally stable along the treatment. CONCLUSION: Removal of interfering LMWCs from inositol-enriched extracts was successfully achieved using a clean and easily scalable fractionation methodology. This biotechnological procedure not only represents high interest for the production of bioactive food ingredients but for applications in other research areas.

Perinatal depression and implementation of the "Thinking Healthy program" support intervention in an impoverished setting of Lima, Peru: Assessment before and during the COVID-19 pandemic.

Socios En Salud (SES) implemented the Thinking Healthy program (THP) to support women with perinatal depression before and during the COVID-19 pandemic in Lima Norte. We carried out an analysis of the in-person (5 modules) and remote (1 module) THP intervention. Depression was detected using PHQ-9, and THP sessions were delivered in women with a score (PHQ-9 ≥ 5). Depression was reassessed and pre- and post-scores were compared. In the pre-pandemic cohort, perinatal depression was 25.4% (47/185), 47 women received THP and 27 were reassessed (57.4%), and the PHQ-9 score median decreased from 8 to 2, p < 0.001. In the pandemic cohort, perinatal depression was 47.5% (117/247), 117 women received THP and 89 were reassessed (76.1%), and the PHQ-9 score median decreased from 7 to 2, p < 0.001. THP's modalities helped to reduce perinatal depression. Pregnant women who received a module remotely also reduced depression.

Mobilizing digital technology to implement a population-based psychological support response during the COVID-19 pandemic in Lima, Peru.

Background: The COVID-19 pandemic caused considerable burden on mental health worldwide. To address this emergency in Peru, Socios en Salud (SES) implemented an innovative digital system for the diagnosis and psychological therapy in vulnerable populations. We describe the development, implementation, and participant outcomes of this intervention. Methods: We conducted an intervention in a general population of Lima, Peru using a digital tool, ChatBot-Juntos, incorporating the abbreviated Self-Reporting Questionnaire (SRQ) to screen psychological distress. Participants positive for psychological distress received remote Psychological First Aid (PFA) and grief therapy if needed. Participants with a mental health condition or safety concern were referred to mental health services. SRQ scores were collected 3 months after PFA sessions. Differences between screening and follow-up scores were compared using Wilcoxon sign-rank test. Results: In total, 2027 people were screened; 1581 (77.9%) screened positive for psychological distress. Nine hundred ninety-seven (63%) people with psychological distress received PFA, and 320 (32.1%) of those were also referred for mental health care. At 3 months after follow-up, SRQ scores were collected for 579 (58%) participants. Significant reduction in SRQ scores was observed 3 months after PFA [median SRQ score changed from 9 to 5 (p < 0.001)], and after PFA plus referral to mental health services [median SRQ score changed from 11 to 6 (p < 0.001)]. Conclusion: Digital technology can be used to screen for psychological distress and deliver mental health support for populations affected by the COVID-19 pandemic. More research is needed to determine whether technology contributes to improved mental health outcomes.

Characteristics, clinical outcomes, and risk factors of SARS-COV-2 infection in adult acute myeloid leukemia patients: experience of the PETHEMA group.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection produces higher morbidity and mortality in hematological malignancies, but evidence in acute myeloid leukemia (AML) is scarce. A multicenter observational study was conducted to determine the clinical outcomes and assess the impact of therapeutic approaches in adult AML patients with SARS-CoV-2 infection in the first wave (March-May 2020). Overall, 108 patients were included: 51.9% with active leukemia and 70.4% under therapeutic schedules for AML. Signs and symptoms of SARS-CoV-2 were present in 96.3% of patients and 82.4% received specific treatment for SARS-CoV-2. The mortality rate was 43.5% and was correlated with age, gender, active leukemia, dyspnea, severe SARS-CoV-2, intensive care measures, neutrophil count, and D-dimer levels. A protective effect was found with azithromycin, lopinavir/ritonavir, and normal liver enzyme levels. During the SARS-CoV-2 first wave, our findings suggested an increased mortality in AML in a short period. SARS-CoV-2 management could be guided by risk factors in AML patients.

High-Dimensional Analysis of Single-Cell Flow Cytometry Data Predicts Relapse in Childhood Acute Lymphoblastic Leukaemia.

Artificial intelligence methods may help in unveiling information that is hidden in high-dimensional oncological data. Flow cytometry studies of haematological malignancies provide quantitative data with the potential to be used for the construction of response biomarkers. Many computational methods from the bioinformatics toolbox can be applied to these data, but they have not been exploited in their full potential in leukaemias, specifically for the case of childhood B-cell Acute Lymphoblastic Leukaemia. In this paper, we analysed flow cytometry data that were obtained at diagnosis from 56 paediatric B-cell Acute Lymphoblastic Leukaemia patients from two local institutions. Our aim was to assess the prognostic potential of immunophenotypical marker expression intensity. We constructed classifiers that are based on the Fisher's Ratio to quantify differences between patients with relapsing and non-relapsing disease. We also correlated this with genetic information. The main result that arises from the data was the association between subexpression of marker CD38 and the probability of relapse.

Specific hypertension smartphone application to improve medication adherence in hypertension: a cluster-randomized trial.

Introduction: Digital interventions, such as smartphone applications (apps), are becoming an increasingly common way to support medication adherence and self-management in chronic illness.Aim: To evaluate the effectiveness of the intervention in pharmacological therapeutic adherence in mild to moderate arterial hypertension (AHT), through an app installed on a mobile phone, as well as the degree of control reached by the patient with this tool.Methods: Prospective, randomized controlled trial, full study and multicenter study. Four primary care centers participated. One hundred and fifty-four hypertensive patients under antihypertensive treatment were included. Two groups were established: a control group (CG) with usual intervention (n = 77) and an intervention group (n = 77) (IG), targeting hypertensive people who owned and regularly used a mobile smartphone, specifically using the app called AlerHTA to promote health education and reminder of appointments. There were three visits: initial, 6 and 12 months. Drug adherence was measured by electronic monitors (MEMSs). The primary outcomes were average daily percentage adherence between 80 and 100%, and AHT control.Results: A total of 148 patients finished the study. Mean age was 57.5 ± 9.9. Global adherence was 77.02% (CI = 70.25-83.79) and daily adherence was 74.32% (CI = 67.29-81.35%). Daily adherence was 93.15% and 86.3% in IG, and 70.66% and 62.66% in CG after 6 and 12 months respectively (p < .05). The percentage of uncontrolled patients was 28.3% (CI = 21.05-35.55%). The control of high blood pressure at 12 months was 17.8% and 38.6% for IG and CG respectively (p < .05). The number of patients needed to treat to avoid non-adherence (NNT) was 4.23 patients.Conclusions: The intervention with an app installed on the mobile phones of hypertensive patients favors pharmacological therapeutic adherence and improves the percentage of hypertensive patient control.Trial registration: Spanish Agency of Medicine: EPA-SP UN-HTA-2015-01.

Extraction and characterization of low molecular weight bioactive carbohydrates from mung bean (Vigna radiata).

Due to the great interest in obtaining natural bioactive carbohydrates to be used as functional ingredients, a selective microwave assisted extraction (MAE) method was optimized to ensure the exhaustive extraction of inositols and α-galactooligosaccharides (α-GOS) from mung bean. Thereafter, a comprehensive characterization of these compounds was carried out by gas chromatography coupled to mass spectrometry (GC-MS). Apart from free inositols and α-GOS, several glycosyl-methyl-scyllo-inositols and glycosyl-inositols were detected for the first time in this legume. Under optimized MAE conditions (0.5 g dry sample, 2 cycles of 3 min, 50 °C, 10 mL 50:50 ethanol:water, v:v), bioactive carbohydrates yields were similar to those found using solid-liquid extraction (SLE), but with shorter analytical times. Concentrations of bioactive carbohydrates in MAE extracts from samples of different geographical origins ranged between 74.1 and 104.2 mg.g-1 dry sample. MAE was proved a good alternative to SLE to obtain extracts enriched in bioactive carbohydrates.

HIV and syphilis testing preferences among men who have sex with men and among transgender women in Lima, Peru.

BACKGROUND: Men who have sex with men (MSM) and transgender women in Peru are at high risk for acquiring syphilis and HIV infection. The World Health Organization highly recommends screening for HIV and syphilis to reduce morbidity and mortality associated with untreated infections. We aimed to identify factors associated with dual testing preferences for HIV and syphilis infection among MSM and transgender women in Lima, Peru. METHODS: We used conjoint analysis, an innovative method for systematically estimating consumer preferences. We created eight hypothetical test profiles varying across six dichotomous attributes: cost (free vs. $4), potential for false positive syphilis result (no false positive vs. some risk of false positive), time-to-result (20 minutes vs. 1 week), blood draw method (finger prick vs. venipuncture), test type (rapid vs. laboratory), and number of draws (1 vs. 2). We fit a conjoint analysis model for each participant using a simple main effects ANOVA. Attribute importance values were calculated using percentages from relative ranges in the attribute's utility values. Results were summarized across participants and averages were reported. RESULTS: We recruited 415 MSM/transgender women over 18 years of age from two STD clinics in Lima, Peru. No potential for syphilis false positive result (no false positive vs. some potential for false positive) had the largest average impact on willingness to use the test and on average accounted for 23.8% of test type preference, followed by cost (free vs. ~USD$4; 21.6%), time to results (20 minutes vs. 1 week; 17.4%), number of blood draws (1 draw vs. 2 draws; 13.8%), method of blood draw (fingerprick vs. venipuncture; 13.7%), and test type (rapid POC vs. laboratory; 9.7%). CONCLUSION: MSM/transgender women in Peru prioritized accuracy, cost, timeliness and number of blood draws for HIV and syphilis testing. Implementing a low cost, accurate, rapid and dual testing strategy for HIV and syphilis could improve screening uptake and accessibility of testing to accelerate time to treatment.

Validation of the electronic prescription as a method for measuring treatment adherence in hypertension.

OBJECTIVE: To validate electronic prescriptions (e-prescriptions) as a method for measuring treatment adherence in patients with hypertension. METHODS: This prospective study initially included 120 patients treated for hypertension in primary care centers. Adherence was measured using the gold standard, the medication event monitoring system (MEMS), versus the index test, the e-prescription program, at baseline and at 6, 12, 18 and 24 months. We calculated the adherence rate using the MEMS and the medication possession ratio (MPR) for the e-prescriptions. We considered patients adherent if they had an adherence rate of 80% to 100%. To validate the e-prescription, we obtained measures of diagnostic accuracy, the Kappa concordance index, and the area under the ROC curve (AUC). RESULTS: We included 102 patients. Overall adherence was 77.4% by MEMS (95%CI: 66.8-88) and 80.4% (95%CI: 70.3-90.5) by MPR. At 24 months, sensitivity was 87% and specificity, 93.7%. The AUC was 0.903 (95%CI: 0.817-0.989). CONCLUSION: Measures of treatment adherence were not significantly different between e-prescription and gold standard at most visits, and the e-prescription showed good discriminatory diagnostic capacity. PRACTICE IMPLICATIONS: If patients are included in an e-prescription program for at least 2 years, e-prescription is an inexpensive method to measure adherence in hypertension.

Recent developments in the analysis of brominated flame retardants and brominated natural compounds.

This article reviews recent literature on the analysis of brominated flame retardants (BFRs) and brominated natural compounds (BNCs). The main literature sources are reviews from the last five years and research articles reporting new analytical developments published between 2003 and 2006. Sample pretreatment, extraction, clean-up and fractionation, injection techniques, chromatographic separation, detection methods, quality control and method validation are discussed. Only few new techniques, such as solid-phase microextraction (SPME) or pressurized liquid extraction (PLE), have been investigated for their ability of combining the extraction and clean-up steps. With respect to the separation of BFRs, the most important developments were the use of comprehensive two-dimensional gas chromatography for polybrominated diphenyl ethers (PBDEs) and the growing tendency for liquid-chromatographic techniques for hexabromocyclododecane (HBCD) stereoisomers and of tetrabromobisphenol-A (TBBP-A). At the detection stage, mass spectrometry (MS) has been developed as well-established and reliable technology in the identification and quantification of BFRs. A growing attention has been paid to quality assurance. Interlaboratory exercises directed towards BFRs have grown in popularity and have enabled laboratories to validate analytical methods and to guarantee the quality of their results. The analytical procedures used for the identification and characterization of several classes of BNCs, such as methoxylated polybrominated diphenyl ethers (MeO-PBDEs) (also metabolites of PBDEs), halogenated methyl or dimethyl bipyrroles (DBPs), are reviewed here for the first time. These compounds were generally identified during the routine analysis of BFRs and have received little attention until recently. For each topic, an overview is presented of its current status.

Determination of toxaphene enantiomers by comprehensive two-dimensional gas chromatography with electron-capture detection.

Comprehensive two-dimensional gas chromatography with micro electron-capture detection (GC x GC-microECD) has been evaluated for the enantioseparation of five chiral toxaphenes typically found in real-life samples (Parlar 26, 32, 40, 44 and 50). From the two enantioselective beta-cyclodextrin-based columns evaluated as first dimension column, BGB-176SE and BGB-172, the latter provided the best results and was further combined with three non-enantioselective columns in the second dimension: HT-8, BPX-50 and Supelcowax-10. The combination BGB-172 x BPX-50 was finally selected because it provided a complete separation among all enantiomers. A satisfactory repeatability and reproducibility of the retention times in both the first and the second dimension were observed for all target compounds (RSDs below 0.8%, n = 4). Linear responses in the tested range of 10-200 pg/microl and limits of detection in the range of 2-6 pg/microl were obtained. The repeatability and reproducibility at a concentration of 100 pg/microl, evaluated as the RSDs calculated for the enantiomeric fraction (EF), was better than 11% (n = 4) in all instances. The feasibility of the method developed for real-life analyses was illustrated by the determination of the enantiomeric ratios and concentration levels of the test compounds in four commercial fish oil samples. These results were compared to those obtained by heart-cut multidimensional gas chromatography using the same enantioselective column.

Extraction of bioactive carbohydrates from artichoke (Cynara scolymus L.) external bracts using microwave assisted extraction and pressurized liquid extraction.

Microwave assisted extraction (MAE) and pressurized liquid extraction (PLE) methods using water as solvent have been optimized by means of a Box-Behnken and 3(2) composite experimental designs, respectively, for the effective extraction of bioactive carbohydrates (inositols and inulin) from artichoke (Cynara scolymus L.) external bracts. MAE at 60 °C for 3 min of 0.3 g of sample allowed the extraction of slightly higher concentrations of inositol than PLE at 75 °C for 26.7 min (11.6 mg/g dry sample vs. 7.6 mg/g dry sample). On the contrary, under these conditions, higher concentrations of inulin were extracted with the latter technique (185.4 mg/g vs. 96.4 mg/g dry sample), considering two successive extraction cycles for both techniques. Both methodologies can be considered appropriate for the simultaneous extraction of these bioactive carbohydrates from this particular industrial by-product. To the best of our knowledge this is the first time that these techniques are applied for this purpose.

Chiral comprehensive two-dimensional gas chromatography with electron-capture detection applied to the analysis of chiral polychlorinated biphenyls in food samples.

The feasibility of comprehensive two-dimensional gas chromatography with electron-capture detection (GC x GC-ECD) for the enantioseparation of chiral PCBs from other possible interfering compounds has been evaluated. Three commercially available enantioselective beta-cyclodextrin-based capillary columns (Chirasil-Dex, BGB-172 and BGB-176SE) have been tested as first-dimension columns. Three non-enantioselective stationary phases (HT-8, BPX-50 and Supelcowax-10) were combined with the enantioselective columns to allow the unambiguous determination of the enantiomers of the target chiral PCBs. Each enantioselective first-dimension column tested was able to separate into enantiomers different PCB congeners, but in all cases, the use of Supelcowax-10 as second-dimension column provided the most satisfactory results. The Chirasil-Dex x Supelcowax-10 column combination allowed the determination of the enantiomeric fraction (EF) of PCBs 84, 91, 95, 132, 136, 149, 174 and 176 in the working standard solution, while that of congener 135 was hindered. The BGB-172 x Supelcowax-10 column set allowed a proper EF determination of congeners 45, 84, 131, 132, 135, 171, 174 and 183, while that of PCB 91 was interfered with co-elutants. The column combination BGB-176SE x Supelcowax-10 allowed the determination of all congeners that this enantioselective stationary phase was able to separate into enantiomers, i.e. PCBs 45, 91, 95, 136, 149 and 176. These column combinations have also been evaluated for the simultaneous determination of the 12 congeners with a toxic equivalency factor assigned by the WHO (PCBs 77, 81, 105, 114, 118, 123, 126, 156, 157, 167, 169, 189) and the seven indicator congeners (PCBs 28, 52, 101, 118, 138, 153 and 180), and evaluated for the analysis of food samples.