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Biomedical subjects

A Laplanche

Publications and source records attributed to A Laplanche.

At least 19 recordsLinked to original sources
PubMed2006

[Role and perspectives of sentinel node biopsy in head and neck tumors].

PURPOSE: To evaluate the accuracy of sentinel node biopsy for assessing the neck status for those patients with squamous cell carcinoma T1T2N0 of oral cavity. PATIENTS AND METHODS: 55 patients were included in a prospective study between 2000 and 2003. 53 underwent a sentinel node biopsy (SNB) followed by an elective neck dissection (END). Pathological examination with stepped serial sectioning and immunohistochemistry of sentinel node (SN) has been compared with routine pathology examination of remaining END nodes. RESULTS: 12 patients had a positive SN. No false negative was found. Patient follow up on, at less of 3 years, did not show any node recurrence for those patients with negative SN. After that study, 44 patients had a SNB without END. 7 patients had a positive SN. Follow up showed a node recurrence for 3 patients. In two of these, pathological reexamination showed a micrometastase in SN. SN failure rate is less than 3% for those 99 patients. CONCLUSION: SNB is a liable procedure. Failure rate is the same as in END. We plan to use this procedure in orophyngeal tumors where it could be possible to reduce irradiation fields and treatment sequels for those patients with negative SN.

Adult↗
PubMed2006

A phase II monocentric study of oxaliplatin in combination with gemcitabine (GEMOX) in patients with advanced/metastatic transitional cell carcinoma (TCC) of the urothelial tract.

BACKGROUND: The aim of the study was to evaluate the activity and the safety of the gemcitabine-oxaliplatin (GEMOX) combination as first-line treatment in advanced/metastatic transitional cell carcinoma (TCC) of the urothelial tract. MATERIALS AND METHODS: Patients with metastatic or unresectable TCC, PS < or =2, creatinine < or =1.5 upper limit of normal range (UNL) and measurable disease according to RECIST criteria were treated with a combination of gemcitabine (1500 mg/m(2)) followed by oxaliplatin (85 mg/m(2)) on day 1 and 15 of a 28-day cycle. RESULTS: A total of 123 cycles were administered to 30 patients (median 4, range 1-8). Three complete responses (CR) and 11 partial responses (PR) were observed. Overall response rate (ORR) was 47% (95% CI 28% to 66%). Median overall survival (OS) was 15 months (95% CI 8-31). Grade 3 and 4 neutropenia were reported in three and one patient, respectively; grade 3 anaemia in three patients; grade 3 and 4 thrombocytopenia in two and one patient, respectively; grade 1, 2 and 3 peripheral neuropathy in 14, 11 and two patients, respectively; grade 2 and 3 fatigue in 13 and seven patients respectively. CONCLUSIONS: The GEMOX combination is active in advanced/metastatic TCC with minimal toxicity and needs to be evaluated in a selected population of unfit patients and compared with other non-cisplatin-containing regimens.

Aged↗
PubMed2006

New compact scrubber for odour removal in wastewater treatment plants.

This work presents the performances of a new odour scrubber. The reactor is packed with a new structure which enables co-current operations at high gas velocities. Energy consumption and removal efficiency of sulphur compounds by oxidative alkaline scrubbing were studied. The influence of both superficial gas (U(SG)) and liquid (U(SL)) velocities, ranging from 5.6 to 28 m.s(-1) and 0.016 to 0.055 m.s(-1) respectively, were quantified. Thus, the range of 0.5 to 5 liquid-to-gas mass ratio (L/G) was studied. A comparison has been made with a previous study on static mixers (SM) and with classical random packed towers (PT). It has been shown that superficial liquid and gas velocities have a significant influence on these parameters. Hydrogen sulphide (H2S) abatement reached values up to 99%. As concerns methylmercaptan (CH3SH), the maximal removal efficiency was 87%. As a result, if well scaled-up, our reactor can be a small single stage efficient apparatus for the elimination of low concentrations of sulphur compounds as H2S and CH3SH in high flow rates of polluted gas effluents.

Air Pollutants↗
PubMed2005

The risk of thrombo-embolic events is increased in patients with germ-cell tumours and can be predicted by serum lactate dehydrogenase and body surface area.

The aim of this study was to evaluate the risk of thrombo-embolic events (TEE) in patients with germ-cell tumours (GCT) who receive cisplatin-based chemotherapy, to compare this risk to that of a matched control group of non-GCT cancer patients, and to identify risk factors of TEE. The rate of TEE during the 6 months following the initiation of chemotherapy was assessed in 100 consecutive patients with GCT and in 100 controls with various neoplasms who were matched on sex and age, and who received first-line cisplatin-based chemotherapy during the same period of time at Institut Gustave Roussy, Villejuif, France. Data were subsequently tested on a validation group of 77 GCT patients treated in Lyon, France. A total of 19 patients (19%) (95% confidence interval (CI): 13-28) and six patients (6%) (95% CI: 3-13) had a TEE in the GCT group and the non-GCT control group, respectively (relative risk (RR): 3.4; P<0.01). Three patients from the GCT group died of pulmonary embolism. In multivariate analysis, two factors had independent predictive value for TEE: a high body surface area (>1.9 m2) (RR: 5 (1.8-13.9)) and an elevated serum lactate dehydrogenase (LDH) (RR: 6.4 (2.3-18.2)). Patients with no risk factor (n=26) and those with at least one risk factor (n=71) had a probability of having a TEE of 4% (95% CI: 1-19) and 26% (95% CI: 17-37), respectively. In the GCT validation set, 10 (13%) patients had a TEE; patients with no risk factor and those with at least one risk factor had a probability of having a TEE of 0 and 17% (95% CI: 10-29), respectively. Patients with GCT are at a higher risk for TEE than patients with non-GCT cancer while on cisplatin-based chemotherapy. This risk can be accurately predicted by serum LDH and body surface area. This predictive index may help to study prospectively the impact of thromboprophylaxis in GCT patients.

Adolescent↗
PubMed2005

Limb salvage with isolated perfusion for soft tissue sarcoma: could less TNF-alpha be better?

BACKGROUND: The optimal dose of TNF-alpha delivered by isolated limb perfusion (ILP) in patients with locally advanced soft tissue sarcoma is still unknown. PATIENTS AND METHODS: Randomised phase II trial comparing hyperthermic ILP (38-40 degrees ) with melphalan and one of the four assigned doses of TNF-alpha: 0.5 mg, 1 mg, 2 mg, and 3/4 mg upper/lower limb. The main end point was objective tumour response on MRI. Secondary end points were histological response, rate of amputation and toxicity. Resection of the remnant tumour was performed 2-3 months after ILP. The sample size was calculated assuming a linear increase of 10% in the objective response rates between each dose level group. RESULTS: One hundred patients (25 per arm) were included. Thirteen per cent of patients had a systemic leakage with a cardiac toxicity in six patients correlated with high doses of TNF-alpha. Objective tumour responses were: 68%, 56%, 72% and 64% in the 0.5 mg, 1 mg, 2 mg and 3 or 4 mg arms, respectively (NS). Sixteen per cent of patients were not operated, 71% had a conservative surgery and 13% were amputated with no difference between the groups. With a median follow-up of 24 months, the 2 year overall and disease-free survival rates (95% CI) were 82% (73% to 89%) and 49% (39% to 59%), respectively. CONCLUSION: At the range of TNF-alpha doses tested, there was no dose effect detected for the objective tumour response, but systemic toxicity was significantly correlated with higher TNF-alpha doses. Efficacy and safety of low-dose TNF-alpha could greatly facilitate ILP procedures in the near future.

Adult↗
PubMed2004

Bilateral germ-cell tumours: 22-year experience at the Institut Gustave Roussy.

The aim of this study was to describe the incidence, clinical and histological characteristics, treatment and long-term follow-up of bilateral germ-cell tumours (BGCT) of the testis in order to determine in what respects they differ significantly from unilateral germ-cell tumours. In all, 31 patients with BGCT had metachronous tumours and 14 had synchronous tumours. Among the metachronous tumours, 61% occurred more than 5 years after the first tumour. The overall incidence of BGCT in patients with testicular germ-cell tumours (TGCT) was 1.9%. The incidence was 3.2% in patients presenting with a seminoma and 1.4 % in patients presenting with a nonseminomatous germ-cell tumour (NSGCT). Patients under 30 years of age at the time of the initial diagnosis had a higher incidence of bilateral tumours compared with older men. The outcome of BGCT was excellent. A high association was found between BGCT, sterility and suspected genetic risk factors for TGCT. These results argue against a systematic contralateral biopsy at diagnosis of first TGCT in all patients, but emphasise the importance of patient education and of the need to better identify patients at risk for a second TGCT. Therapeutic indications for synchronous BGCT, including conservative treatment, need to be better defined.

Adolescent↗
PubMed2004

Adsorption-oxidation of hydrogen sulfide on activated carbon fibers: effect of the composition and the relative humidity of the gas phase.

The removal of hydrogen sulfide by oxidation-adsorption on two type carbon fibers, Actitex FC1201 and RS1301, was studied. Two kinetic steps where identified. During the first step, the degradation appears to be limited by the oxidation reaction. In the second kinetic step, the by-products inhibit the hydrogen sulfide degradation. This leads to a limitation in the carbon site's accessibility and to a lower kinetic. The Langmuir-Hinshelwood model was used to correlate the experimental results and to estimate the kinetic (k) and the Langmuir adsorption (K) constants. For FC1201 fibers, the kinetic constant (k) is five time higher and the adsorption constant is five time lower compared to the RS1301 fibers. The role of the humidity was found to be highly beneficial for the removal of hydrogen sulfide. Especially in the second kinetic step, where it removes the by-product formed and therefore delays the occurrence of this low kinetic step. The kinetic constant (k) is strongly influenced by humidity while the Langmuir adsorption constant (K) seems independent. The effect of the nature of the gas phase on the reaction kinetic was also studied. Under a dry atmosphere, we note that the oxidation-reaction occurs even if the gaseous oxygen is not present. This oxidation is due to the oxygen surface function of the carbon fibers. Moreover, the degradation kinetic is faster under a dry nitrogen atmosphere. The presence of water traces leads to the acidification of the carbon surface, under oxygen or carbon dioxide atmospheres, and hence limits the hydrogen sulfide dissociation. In a humid atmosphere, the oxygen or carbon dioxide leads to a faster reaction kinetic. The acidification of the carbon surface is largely counterbalanced by the dissolution of the by-products.

Adsorption↗
PubMed2004

Use of hydrogen peroxide in scrubbing towers for odor removal in wastewater treatment plants.

The aim of this work was to replace sodium hypochlorite (NaCIO) with hydrogen peroxide (H202) in chemical scrubbing towers, in order to avoid the formation of chlorinated species, harmful for human health. Some previous studies have already shown the ability of H2O2 to treat the hydrogen sulfide (H2S) pollution. However, an important decomposition of the oxidant was observed in the scrubbing solution (carbonates, transition metal and high pH are responsible for this decomposition) leading to high reactant consumption. Consequently, this study first focused on research into a compound able to reduce the hydrogen peroxide degradation. Experiments were conducted on a pilot unit (3,000 m3 h(-1)) in a wastewater treatment plant. The sodium silicate (Na2SiO3) proved to be a good scrubbing solution stabilizer. A very good removal of hydrogen sulfide (up to 98%) was also obtained. Finally, the study resulted in the determination of the best operating conditions to achieve both an efficient and economical process.

Air Pollutants↗
PubMed2004

[Modalities of radiotherapy in small cell lung cancer: thoracic radiotherapy and prophylactic cerebral irradiation].

Small cell lung cancers (SCC) represent 20% of all lung cancers. After the initial control of the extension, only one third of the patients with SCC will finally have limited disease. The treatment of limited SCC currently relies on chemo-radiotherapeutic combinations that have improved overall survival and survival without metastases over the last few years. Nevertheless, even in limited forms, survival at 5 years varies from 10 to 15% and rarely exceeds 25% in the best series. The risk of relapse is high: although around 70% of patients with a limited form will have complete response, only 15 to 20% of them will exhibit prolonged survival. Indeed, most patients relapse, and the risk of cerebral dissemination for example is particularly high, reaching 50% at 2 years even in complete responders. After the results of a meta-analysis evaluating prophylactic cranial irradiation (PCI) among SCC complete responders, demonstrating 5% enhancement of survival at 3 years, PCI is part of the standard management of SCC in complete response. Despite the improvement in overall survival with the combined treatments, the mediocre results observed in terms of long-term survival warrant further clinical trials in order to define the optimal polychemotherapeutic and radiotherapeutic modalities, the best means of combining these two therapies and the place for new therapies.

Brain Neoplasms↗
PubMed2002

Granulocyte colony-stimulating factor in induction treatment of children with non-Hodgkin's lymphoma: a randomized study of the French Society of Pediatric Oncology.

PURPOSE: To determine whether granulocyte colony-stimulating factor (G-CSF; lenograstim) decreases the incidence of febrile neutropenia after induction courses in treatment of childhood non-Hodgkin's lymphoma (NHL). PATIENTS AND METHODS: Patients were randomized to receive (G-CSF+) or not receive (G-CSF-) prophylactic G-CSF, 5 microg/kg/d, from day 7 until an absolute neutrophil count > or = 500/microL was sustained over 48 hours, after two consecutive induction courses of cyclophosphamide 1.5 or 3 g/m(2), vincristine 2 mg/m(2), prednisone 60 mg/m(2)/d x 5, doxorubicin 60 mg/m(2), high-dose methotrexate 3 or 8 g/m(2), and intrathecal injections (COPAD[M]) on protocols LMB89, LMT89, and HM91 of the French Society of Pediatric Oncology. RESULTS: One hundred forty-eight patients were assessable, 75 G-CSF+ and 73 G-CSF-. Although duration of neutropenia less than 500/microL was 3 days shorter in G-CSF+ patients (P = 10(-4)), incidence of febrile neutropenia (89% v. 93% in the first course, 88% v. 88% in the second course), durations of hospitalization and antimicrobial therapy, percentages of infections, mucositis, and transfusions were not significantly different. Although the percentage of G-CSF+ patients commencing the following course on day 21 was significantly higher (84% v 68% after the first and 57% v. 38% after the second course; P <.05), the median delay between the two courses was only 1 day less in G-CSF+ patients (median delay after first COPAD(M), 19 v. 20 days, P =.01; after second, 21 v. 22 days, P = not significant). Remission and survival rates were similar in both arms. CONCLUSION: This study demonstrates that G-CSF did not decrease treatment-related morbidity, nor increase the dose-intensity in children undergoing COPAD(M) induction chemotherapy for NHL.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2002

Medullary thyroid carcinoma as part of a multiple endocrine neoplasia type 2B syndrome: influence of the stage on the clinical course.

BACKGROUND: Multiple endocrine neoplasia type 2B (MEN 2B) is an exceptional syndrome, for which the optimal age of thyroidectomy is poorly established and the course of medullary thyroid carcinoma (MTC) is ill-defined. PATIENTS: All the 18 patients with a MEN 2B syndrome examined at the Institut Gustave Roussy were included in a single-center retrospective study. RESULTS: There were 9 men and 9 women with a mean age of 13 years (range, 2-27 years) at diagnosis. The diagnosis of MTC was based on the presence of a thyroid nodule or involved neck lymph nodes and on dysmorphic features of MEN 2B in 60% and 40% of the cases, respectively. The classic M918T mutation in exon 16 was found in the 16 patients in whom it was investigated. At diagnosis, 2 patients had Stage I MTC, 15 patients had Stage III, and 1 patient had Stage IV disease. T1 MTC was found in 4 patients aged 2.1-3.7 years. However, two of these patients already had N1 disease. One patient with Stage I MTC, aged 3.4 years and 2 patients with Stage III disease, aged 14 and 25 years, had undetectable basal calcitonin (CT) after initial surgery. During follow-up, basal CT became detectable in one of three patients. Among the 15 other patients with an elevated postoperative CT level, metastases were demonstrated in 5 patients after a mean follow-up of 2 years. Five patients died, three of MTC, one of the MEN 2B syndrome, and one of intercurrent disease. Five- and 10-year overall survival rates were 85% and 75%, respectively. CONCLUSIONS: This study confirms the need for early treatment of MTC in patients with the MEN 2B syndrome, preferably within the first 6 months of life. The phenotype of MTC occurring in the MEN 2B syndrome was not more aggressive than sporadic MTC or MTC occurring in other familial syndromes.

Adolescent↗
PubMed2002

Importance of surface diffusivities in pesticide adsorption kinetics onto granular versus powdered activated carbon: experimental determination and modeling.

Three pesticides (atrazine, bromoxynil and diuron) and two granular activated carbons are involved in equilibrium and kinetic adsorption experiments. Equilibrium is represented by Freundlich isotherm law and kinetic is described by the Homogeneous Surface Diffusion Model, based on external mass transfer and intraparticle surface diffusion. Equilibrium and long-term experiments are conducted to compare Powdered Activated Carbon and Granular Activated Carbon. These first investigations show that crushing GAC into PAC improves the accessibility of the adsorption sites without increasing the number of these sites. In a second part, kinetics experiments are carried out using a Differential Column Batch Reactor. Thanks to this experimental device, the external mass transfer coefficient k(f) is calculated from empirical correlation and the effect of external mass transfer on adsorption is likely to be minimized. In order to obtain the intraparticle surface diffusion coefficient D. for these pesticides, comparisons between experimental kinetic data and simulations are conducted and the best agreement leads to the Ds coefficient. This procedure appears to be an efficient way to acquire surface diffusion coefficients for the adsorption of pesticides onto GAC. Finally it points out the role of surface diffusivity in the adsorption rate. As a matter of fact, even if the amount of the target-compound that could be potentially adsorbed is really important, its surface diffusion coefficient may be small, so that its adsorption may not have enough contact time to be totally achieved.

Adsorption↗
PubMed2002

Patterns of failure after prophylactic cranial irradiation in small-cell lung cancer: analysis of 505 randomized patients.

BACKGROUND: Prophylactic cranial irradiation (PCI) has a beneficial effect on overall survival in patients with small-cell lung cancer (SCLC) in complete remission as shown in a worldwide meta-analysis. The current analysis aimed to evaluate PCI effects on patterns of failure in this patient category. PATIENTS AND METHODS: The Institut Gustave-Roussy coordinated two parallel randomized studies including a total of 511 patients with SCLC. Patients were randomly assigned to either PCI (24 Gy in eight fractions and 12 days) or no PCI. Patterns of failure were analyzed according to (i) total event rates and (ii) isolated first site of relapse using a competing risk approach. RESULTS: Five hundred and five patients were analyzed. The 5-year cumulative rate of brain metastasis as an isolated first site of relapse was 37% in the control group and 20% in the PCI group (P < 0.001). The overall 5-year rates of brain metastasis were 59% and 43%, respectively [relative risk (RR) 0.50; P < 0.001]. The 5-year overall survival rates were 15% in the control group and 18% in the PCI group (RR 0.84; P = 0.06). CONCLUSIONS: PCI decreased significantly the risk of brain metastasis. Other events were not influenced. The relative death risk reduction was of borderline significance. Results reported as isolated first cause of failure and subsequent competing events may explain why a major treatment effect on brain metastases rate has a rather moderate effect on survival.

Adult↗
PubMed2002

Phase II trial of thalidomide in renal-cell carcinoma.

BACKGROUND: Thalidomide has been reported to yield anti-tumor activity in cancer. We performed a phase II trial of this drug in patients with metastatic renal cell carcinoma to determine its efficacy. PATIENTS AND METHODS: Patients with proven metastatic renal cell cancer, measurable progressive disease and a performance status of 0-2 were enrolled in this study. Thalidomide was given daily at a starting dose of 400 mg, followed by a 400 mg increment to 800 mg and then to 1200 mg with 6-12 weeks at each dose level. The response rate at 6 months was the primary end point. Toxicity, overall survival, tumor vascularization depicted on color Doppler ultrasonography and serum vascular endothelial growth factor, basic fibroblast growth factor, interleukin-12 and tumor necrosis factor-alpha levels were secondary end points. RESULTS: Forty patients were enrolled. Two partial responses were observed (5%) and disease remained stable in nine patients after 6 months. Median survival was 10 months. Toxicity was high, with frequent manifestations of fatigue, constipation and lethargy. The incidence of neuropathy detected on electromyography (EMG) attained 70% at 6 months, and 100% in patients on thalidomide for 12 months. Nine patients developed venous thromboembolism during the first 12 weeks of treatment, and three of them experienced pulmonary embolism. One unexpected (and unexplained) death occurred. CONCLUSIONS: Despite undisputed, albeit marginal, activity in renal cell cancer, high-dose thalidomide cannot be recommended using this schedule since the level of toxicity is high.

Adult↗
PubMed2002

[Pheochromocytomas and CT: can size predict malignancy?].

OBJECTIVES: The purpose of this study was to determine clinical and imaging findings associated with malignancy in pheochromocytomas. MATERIAL: and methods. A multicentric retrospective CT study including 50 lesions (23 benign and 27 malignant histologically proven pheochromocytomas) was conducted. The diagnosis of malignancy was based on histological criteria (capsular rupture, local invasion), on synchronous metastases or on the occurrence of locoregional recurrences or metastases during the outcome. The analysis was based on clinical data (age, sex, secretion of the lesion and hypertension) and on radiological criteria (largest diameter of the tumor, side, homogeneity, regularity and sharpness of contours). RESULTS: A statistical difference was found between the median largest diameter, the regularity and sharpness of contours benign and malignant lesions (p<0.0001); other clinical and radiological criteria being non significantly different. A largest diameter greater than 45 mm enabled to suggest malignancy with a sensitivity of 100% and a specificity of 69%. CONCLUSION: A diameter larger than 50mm, presence of a locoregional invasion and of metastases are strong arguments favouring.

Adolescent↗
PubMed2001

Impact of monitoring plasma 1,1-dichlorodiphenildichloroethane (o,p'DDD) levels on the treatment of patients with adrenocortical carcinoma.

BACKGROUND: It has been suggested recently that 1,1-dichlorodiphenildichloroethane (o,p'DDD) elicits a dose effect relation in the treatment of patients with adrenocortical carcinoma (ACC). The authors performed a single-center, prospective study with two major objectives: 1) to confirm the interest of plasma o,p'DDD level measurement as a prognostic factor of response to o,p'DDD therapy; and 2) to look for parameters associated with a therapeutic plasma o,p'DDD level, especially the daily o,p'DDD dose. METHODS: Since 1995, patients with ACC who were referred to the Gustave-Roussy Institute have been enrolled prospectively in the study. Therapy with o,p'DDD was given as first-line therapy in 13 patients with metastatic disease or as adjuvant therapy in 11 patients. Oral o,p'DDD was given in three separate doses up to at least 6-12 g per day together with substitutive adrenal therapy. Plasma o,p'DDD levels were measured using high-performance liquid chromatography every 2 months. The o,p'DDD therapy was monitored to achieve plasma o,p'DDD levels within 14-20 mg/L. World Health Organization criteria were used to evaluate tumor response and toxicity. RESULTS: Twenty-four patients with ACC were studied, and a plasma o,p'DDD level > 14 mg/L was achieved in 14 patients (58%). An objective tumor response was observed in four patients with metastatic lesions (31%): One was response was complete, and three were objective hormonal responses. These tumor responses were observed among the six patients who achieved therapeutic plasma o,p'DDD levels. In contrast, no response was observed among the seven patients with plasma o,p'DDD levels that remained consistently low. Eight of 11 patients who received o,p'DDD as adjuvant therapy had disease recurrence, although the plasma o,p'DDD level was > 14 mg/L in 6 patients. Grade 3 or 4 neurologic toxicity was observed in three patients (12%), all with an o,p'DDD level > 20 mg/L. The daily o,p'DDD dose was the only parameter associated with the highest plasma o,p'DDD trough levels: It explained 35% of the variability in the plasma o,p'DDD level. A median interval of 3.7 months was found necessary to achieve the highest o,p'DDD trough levels. CONCLUSIONS: The results confirm the prognostic impact of the plasma o,p'DDD level in patients with metastatic ACC and its interest in avoiding toxicity.

Adrenal Cortex Neoplasms↗
PubMed2001

Determination of polychlorodibenzo-p-dioxins and polychlorodibenzofurans by gas chromatography/tandem mass spectrometry and gas chromatography/triple mass spectrometry in a quadrupole ion trap.

The determination of tetra- to octachlorodibenzo-p-dioxins and tetra- to octachlorodibenzofurans (PCCD/Fs) by high-resolution gas chromatography/tandem mass spectrometry (HRGC/MS/MS) and high-resolution gas chromatography/triple mass spectrometry (HRGC/MS(3)) in a quadrupole ion trap, equipped with an external ion source, is presented. MS/MS involves a typical four-step process, namely ionization, parent ion isolation, collision-induced dissociation (CID) and mass analysis of the daughter ions. For the MS(3) experiment, the MS/MS scan function is used with the addition of selected daughter ion isolation, their CID and the mass analysis of second-generation product ions called 'grand-daughter ions.' For both methods, the energies necessary for the CID of the 17 PCDD/Fs were determined and optimized using multiple scan functions with different CID amplitudes. The CID efficiency, defined as the signal ratio of fragment ions detected from the major dissociation channels to molecular ions isolated, was 1.15-2.40 V for parent ion dissociation (MS/MS) and 1.05-1.50 V for daughter ion dissociation (MS(3)) and for all the chloro congeners. The same sensitivity (1 pg microl(-1)) can be reached with both the MS/MS and MS(3) methods and linear responses were obtained between 1 and 100 pg microl(-1) injected.

Journal Article↗