Prognostic significance of OX40+ lymphocytes in tumor stroma of surgically resected small-cell lung cancer.

OX40 (CD134) is a co-stimulatory molecule mostly expressed on activated T lymphocytes. Previous reports have shown that OX40 can be an immuno-oncology target and a clinical biomarker for cancers of various organs. In this study, we collected formalin-fixed paraffin-embedded tumor samples from 124 patients with small-cell lung cancer (SCLC) who had undergone surgery. We analyzed the expression profiles of OX40 and other relevant molecules, such as CD4, CD8, and Foxp3, in tumor stroma and cancer nest using immunohistochemistry and investigated their association with survival. High infiltration of OX40+ lymphocytes (OX40high) in tumor stroma was positively associated with relapse-free survival (RFS) and overall survival (OS) compared with low infiltration of OX40+ lymphocytes (OX40low) (RFS, median, 26.0 months [95% confidence interval (CI), not reached (NR)-NR] vs 13.2 months [9.1-17.2], p = .024; OS, NR [95% CI, NR-NR] vs 29.8 months [21.3-38.2], p = .049). Multivariate analysis revealed that OX40high in tumor stroma was an independent indicator of prolonged RFS. Moreover, RFS of patients with OX40high/CD4high in tumor stroma was significantly longer than that of patients with OX40low/CD4low. The RFS of patients with tumor stroma with OX40high/CD8high was significantly longer than that of patients with tumor stroma with OX40low/CD8high, OX40high/CD8low, or OX40low/CD8low. These findings suggest that OX40+ lymphocytes in tumor stroma play a complementary role in regulating the relapse of early-stage SCLC. Reinforcing immunity by coordinating the recruitment of OX40+ lymphocytes with CD4+ and CD8+ T cells in tumor stroma may constitute a potential immunotherapeutic strategy for patients with SCLC.

Delta-like 1 homolog (DLK1) as a possible therapeutic target and its application to radioimmunotherapy using 125I-labelled anti-DLK1 antibody in lung cancer models (HOT1801 and FIGHT004).

OBJECTIVES: Delta-like 1 homolog (DLK1) is a non-canonical Notch ligand known to be expressed in several cancers but whose role in lung cancer is not yet fully understood. We sought to confirm DLK1 expression in small-cell lung cancer (SCLC) and non-small-cell lung cancer (NSCLC), and to examine DLK1's clinical significance. Furthermore, we examined the possible utility of DLK1 as a novel target in radioimmunotherapy (RIT). METHODS: We retrospectively assessed the correlation between clinical features and DLK1 expression by immunohistochemistry in resected specimens from 112 patients with SCLC and 101 patients with NSCLC. Moreover, we performed cell and animal experiments, and examined the possibility of RIT targeting DLK1 in SCLC using iodine-125 (125I) -labeled anti-DLK1 antibody, knowing that 125I can be replaced with the alpha-particle-emitter astatine-211 (211At). RESULTS: In SCLC and NSCLC, 20.5 % (23/112) and 16.8 % (17/101) of patients (respectively) had DLK1-positive tumors. In NSCLC, DLK1 expression was associated with recurrence-free survival (P < 0.01) but not with overall survival. In SCLC, there was no association between DLK1 expression and survival. In addition, 125I-labeled anti-DLK1 antibody specifically targeted DLK1 on human SCLC tumor cell lines. Furthermore, 125I-labeled anti-DLK1 antibody was incorporated into tumor tissue in a mouse model. CONCLUSION: A proportion of SCLC and NSCLC exhibits DLK1 expression. As a clinical feature, DLK1 expression could be a promising prognostic factor for recurrence in patients with resected NSCLC. In addition, DLK1 could serve as a new therapeutic target, including RIT, as suggested by our pilot study using a radiolabeled anti-DLK1 antibody in SCLC.

Thoracoscopic Bronchial Artery Resection for Multiple Bronchial Artery Aneurysms.

We describe a 36-year-old asymptomatic female with multiple bronchial artery aneurysms (BAAs) and a bronchial artery (BA) to pulmonary artery (PA) fistula. She was treated with thoracoscopic BA resection without lobectomy in lieu of catheter embolization as first-line treatment. The configuration of the BA and the location of the BAAs were clearly visualized using three-dimensional computed tomography (3DCT); therefore, the segment of the BA to resect was assessed preoperatively and complete resection of all BAAs was performed. Preoperative BA angiography delineated the BA to PA fistula, and guided surgical decision-making.

Detection of somatic TP53 mutation in surgically resected small-cell lung cancer by targeted exome sequencing: association with longer relapse-free survival.

OBJECTIVES: Few reports have explored clinical biomarkers, including those identified by targeted exome sequencing (TES) of surgically resected small-cell lung cancer (SCLC) and correlation with patient survival. PATIENTS AND METHODS: We collected formalin-fixed paraffin-embedded tumor samples from 127 patients with SCLC who had undergone surgery and analysed nonsynonymous somatic gene mutation profiles by TES of 26 cancer-related genes using next-generation sequencing (NGS) and web databases (UMIN Registration No. 000010117). RESULTS: We detected 38 nonsynonymous somatic tumor protein p53 (TP53) mutations in 43 (54.4%) patients. Among these TP53 lesions, we identified clinically relevant mutations including those encoding Y220C, R248W, R249M, M237I, and R273L substitutions in the p53 protein. These mutations have been reported to be associated with certain clinical outcomes or biology in other types of malignancies but not in SCLC. Moreover, nonsynonymous somatic mutations of TP53 were positively associated with relapse-free survival (RFS) (median, 17.33 months [95% confidence interval (CI), 3.86-30.79] in a mutation-positive group vs 10.39 months (6.96-13.82) in a mutation-negative group, p = 0.042). Multivariate analysis revealed that nonsynonymous somatic TP53 mutation was an independent factor of prolongation of RFS (hazard ratio: 0.51, 95% CI: 0.29-0.89, p = 0.019) but not overall survival (OS). CONCLUSION: These data suggested that TES may play a critical role for promoting reverse-translational studies, including investigations of the biology of TP53 mutations in different stages of SCLC. Accumulation of the data using cancer panels with a broader range of genes, including TP53, is expected to be useful for future clinical applications for patients with SCLC.

Analysis of DLL3 and ASCL1 in Surgically Resected Small Cell Lung Cancer (HOT1702).

BACKGROUND: Delta-like protein 3 (DLL3) is a Notch ligand that has an important role in the tumorigenesis of small cell lung cancer (SCLC). Recently, rovalpituzumab tesirine (Rova-T), a DLL3-targeted antibody-drug conjugate, has been developed for treating SCLC. DLL3 is a transcriptional target of the achaete-scute homolog-1 (ASCL1) transcription factor, which is involved in pulmonary neuroendocrine cell development. However, the relationship between DLL3 and/or ASCL1 expression and the clinical features of SCLC remains unknown, especially for early-stage resected SCLC. This study aimed to investigate the expression of DLL3 and ASCL1 in resected SCLC samples using immunohistochemical analysis. MATERIALS AND METHODS: We collected 95 surgically resected SCLC samples, which were formalin fixed and paraffin embedded. Immunohistochemistry staining was performed to investigate the correlation between the expression of either DLL3 or ASCL1 and clinicopathological features of study patients. RESULTS: Seventy-seven (83%) of 93 immunohistochemically evaluable samples were positive for DLL3 (expression in ≥1% of tumor cells), and DLL3-high expression (≥75%) was observed in 44 samples (47%). Sixty-one (64%) of 95 samples were positive for ASCL1 (expression in ≥5% of tumor cells). A positive correlation was observed between DLL3 and ASCL1 expression. DLL3 and ASCL1 expression were not associated with survival in SCLC patients. DLL3 was more prevalent in patients with advanced clinical disease. CONCLUSION: DLL3 and ASCL1 were highly expressed in patients with surgically resected SCLC. DLL3 and ASCL1 may be targets for the treatment of SCLC. IMPLICATIONS FOR PRACTICE: This article examines the relationship between delta-like protein 3 (DLL3) and achaete-scute homolog-1 (ASCL1) protein expression with the clinical features of 95 surgically resected small cell lung cancer (SCLC). DLL3 is attracting attention because rovalpituzumab tesirine (Rova-T), a DLL3-targeted antibody-drug conjugate, was developed recently. DLL3 and ASCL1 were highly expressed in patients with surgically resected SCLC. DLL3 and ASCL1 may be targets for the treatment of early-stage SCLC, including with Rova-T.

Polypoid pulmonary arteriovenous malformation causing hemothorax treated with thoracoscopic wedge resection.

BACKGROUND: Pulmonary arteriovenous malformations (PAVMs) can be associated with life-threatening complications such as paradoxical embolization, cerebral abscess, and hemothorax. Therefore, all adults with PAVMs should be offered treatment. Percutaneous transcatheter embolization is the first-line treatment, but 5-25% of cases require further treatment due to persistence after embolization. Recently, the role of minimally invasive thoracic surgery as a definitive treatment has been evaluated. We describe a case of a small peripheral PAVM causing hemothorax, which was safely treated with video-assisted thoracoscopic surgery (VATS). In our case, the PAVM appeared to protrude into the pleural cavity on chest computed tomography (CT), perhaps explaining why it led to a hemothorax. CASE PRESENTATION: A 64-year-old man with a history of a brain abscess, for which he underwent surgery 6 months previously, developed a left-sided hemothorax. He had experienced recurrent epistaxis and received anticoagulation therapy for chronic atrial fibrillation. Chest CT after drainage revealed a solitary 15-mm nodule in the periphery of the left lower lobe, and identification of a feeding artery and draining vein on three-dimensional CT suggested that the node was a PAVM. The PAVM was adjacent to the diaphragm and multi-detector CT (MDCT) and three-dimensional CT (3DCT) showed that the nodule slightly displaced the diaphragm and protruded into the pleural cavity. After discussion in a multidisciplinary conference, it was decided that surgical treatment would be preferable to catheter embolization. The patient underwent VATS with three ports, the largest of which was 15 mm. The PAVM protruded from the peripheral lung like a polyp, and wedge resection was performed after simple adhesiolysis. There were no complications, and the patient is asymptomatic after 1-year of follow-up. CONCLUSIONS: As in the present case, PAVMs protruding into the pleural cavity can cause hemothorax, and surgical wedge resection of the involved lung as a definitive treatment is feasible and possibly safer than catheter embolization, particularly if the PAVM is localized close to the visceral pleura. Protrusion into the pleural cavity (polypoid appearance) was detected using MDCT and 3DCT preoperatively.

Expression of Notch1 and Numb in small cell lung cancer.

Notch signaling in tumorigenesis functions as an oncogene or tumor suppressor according to the type of malignancy. Numb represses intracellular Notch signaling. Previous studies have demonstrated that Notch signaling suppresses the proliferation of small cell lung cancer (SCLC) cell lines. However, in SCLC, the association between Notch1 and Numb expression and clinicopathological factors or prognosis has remained unclear. In this study, we evaluated the expression of Notch1 and Numb in SCLC. We immunohistochemically assessed 125 SCLCs that were surgically resected at 16 institutions participating in either the Hokkaido Lung Cancer Clinical Study Group Trial (HOT) or the Fukushima Investigative Group for Healing Thoracic Malignancy (FIGHT) between 2003 and 2013. Correlations between Notch1 or Numb expression and various clinicopathological features were evaluated. Notch1 expression was associated with ECOG performance status. Numb expression was associated with age, sex, and pathological histology (SCLC or Combined SCLC). Analysis of cellular biological expression did not demonstrate a significant correlation between the expression of Notch1 and of Numb. Multivariate Cox regression analysis showed that high Notch1 expression was an independent favorable prognostic factor for SCLC(hazard ratio = 0.503, P = 0.023). High Notch1 expression, but not Numb expression, is associated with favorable prognosis in SCLC.

Immunohistochemical profiling of receptor tyrosine kinases, MED12, and TGF-ßRII of surgically resected small cell lung cancer, and the potential of c-kit as a prognostic marker.

The limited number of available treatments for patients with small-cell lung cancer (SCLC) has prompted us to further investigate the biology of SCLC by molecular profiling. We collected formalin-fixed paraffin-embedded tumor samples from 127 patients with SCLC, who had undergone surgery at 16 institutions between January 2003 and January 2013, and analyzed the association between disease-specific survival and protein expression of c-kit, c-Met, epidermal growth factor receptor, human EGFR-related 2, vascular endothelial growth factor receptor II, anaplastic lymphoma kinase, mediator complex subunit 12 (MED12), and transforming growth factor beta receptor II (TGF-ßRII) by immunohistochemistry (IHC). Of the 125 evaluable samples, all tumors expressed MED12, and 123 samples (98.4%) expressed TGF-ßRII. MED12 was highly expressed in the nucleus in 92% of the positive samples while TGF-ßRII was highly expressed in the cytoplasm in 55% of the positive samples. High c-kit expression was an independent favorable prognostic marker confirmed by multivariate analysis (hazard ratio: 0.543, 95% confidence interval: 0.310-0.953, p = 0.033). Both the relapse free-survival and overall survival of patients who underwent adjuvant chemotherapy were statistically longer in those with high c-kit expression (n = 38) than those with intermediate, low, or no c-kit expression (n = 19) (not reached vs 11.6 months, p = 0.021; not reached vs 25.9 months, p = 0.028). IHC for c-kit may offer a prognostic marker for early-stage SCLC, and the results for MED12 and TGF-ßRII may suggest the biological characteristics of SCLC. Further investigation of the roles of their related molecules in early stage SCLC is required.

Ultra-sensitive HPLC-photochemical reaction-luminol chemiluminescence method for the measurement of secondary amines after nitrosation.

A novel method for the determination of secondary amines at the nanomolar level was developed. The method is based on the nitrosation reaction of secondary amines, with the generated N-nitrosamines being measured using an HPLC separation, photochemical reaction, and chemiluminescence detection system. The efficient nitrosation of secondary amines was performed using sodium nitrite (200 mM) and acetic acid (0.8 M) at 80 °C over 60 min. Although compounds bearing OH and SH functional groups also underwent the nitrosation reaction, the sensitivity of these compounds was 1000 times lower than that of the secondary amines. Our method was applied to the determination of low molecular weight secondary amines, including dimethylamine, morpholine, pyrrolidine, diethylamine, and piperidine, giving method detection limits of 0.7 nM, 0.2 nM, 0.4 nM, 0.7 nM, and 1.5 nM, respectively. The calibration curves were linear in the range of 5-100 nM. We then applied this method for the detection and quantification of these secondary amines in samples of tap water, river water, treated wastewater, and sea water. Dimethylamine was detected at concentrations up to 15.4 nM, <0.7 nM, and 48.5 nM in tap water, river water, and treated wastewater samples, respectively, with recoveries ranging from 94 to 103%. Other amines were also detected at nanomolar levels. These results indicate that our proposed method can be applied to the analysis of secondary amines in various environmental water samples. To the best of our knowledge, the proposed method is one of the most sensitive and selective methods for the determination of secondary amines without pre-concentration steps.

In-line System to Produce High-Purity Acid Solutions.

Herein, we report a new device that generates a high-purity acid solution. It comprises three compartments divided by anion-exchange membranes and filled with ion-exchange resins. Fluorochemical cation-exchange membranes, which tolerate electrochemical wear and permit bulk flow, are inserted between each electrode and the anion-exchange resin. A bipolar boundary is a composite boundary comprising anion and cation exchangers. This device has four bipolar boundaries to separate the location of acid generation from the location where water is electrolyzed. It can tolerate high pressures, resist degradation due to electrolysis at the electrodes, and produce high-purity acid solutions that are free from gases and cationic impurities. The acid solution is generated on the basis of an electrokinetic phenomenon at the surfaces of ion-exchange resins and membranes in an electric field; its concentration can be controlled at rates from 0.01 to 100 µmol/min by adjusting the electrical current applied to the device.

Device to generate high purity hydroxide solution in-line for ion chromatography.

Herein, we report a new device that generates a high-purity hydroxide solution in line. The device's container has three compartments that are isolated from each other by two cation exchange (CE) membranes. In each end of the container, an electrode is installed. The three compartments are filled with ion exchange resins. A bipolar boundary is a composite boundary comprising anion- and cation-exchangers. This device has two bipolar boundaries, which are used to separate the location of hydroxide solution generation from the location where water is electrolyzed. Therefore, it can produce high-purity hydroxide solutions that are free from gases and anionic impurities. The hydroxide solution is generated on the basis of an electrokinetic phenomenon at the surfaces of ion-exchange resins and membranes in an electric field; NaOH concentration can be controlled at rates from 0.01 to 100mM per 1mL/min by adjusting the electrical current (0-200mA) applied to the device. As the generated solution is used as an eluent for a suppressed anion chromatography, the electrical conductivity of the effluent from the suppressor is as low as that of ultra-pure water. Thus, the noise of the base-line electrical conductivity is improved, and so the detection limit of anions on the sub-ng/mL order can be achieved.

Prognostic impact of clinical variables on surgically resected small-cell lung cancer: Results of a retrospective multicenter analysis (FIGHT002A and HOT1301A).

OBJECTIVES: Several American and Japanese guidelines recommend surgery for patients with c-stage I small-cell lung cancer (SCLC), whereas the European Society of Medical Oncology (ESMO) guidelines recommend surgery for patients with not only c-stage I but also c-stage II (T2N1) SCLC. In addition, previous studies identified various factors other than clinical stage that are related to survival in these patients. Thus, further validation and examination of the association of clinical stage and other clinical variables with survival are required for establishing practical management of early-stage SCLC. PATIENTS AND METHODS: We reviewed the clinical courses of 156 SCLC patients who had undergone surgery at 17 institutions between January 2003 and January 2013. RESULTS: Clinical stages (tumor-node-metastasis [TNM] version 7) of the 156 patients were 98 cases in IA, 14 in IB, 16 in IIA, 7 in IIB, 18 in IIIA, and 3 in IIIB. Median overall survival (OS) was 33.3 months (95% confidence interval: 20.9-45.8). Multivariate analysis revealed that OS was longer in patients either at c-stage II and under, with a maximum tumor diameter of <20mm, with preoperative diagnosis, without a history or presence of other types of cancer, or who underwent prophylactic cranial irradiation (PCI). CONCLUSION: These results indicate that a history or presence of other types of cancer might be a major decisive factor for surgery. Patients with c-stages I and II (c-T2N1) can be considered for surgery, and PCI may be useful in patients undergoing surgery in a practical setting, partly supporting the ESMO guidelines.(1).

Bronchogenic cyst associated with congenital absence of the pericardium.

We report a rare case of bronchogenic cyst associated with congenital complete absence of the pericardium. A 17-year-old male was admitted to the hospital for surgical resection of a growing cystic lesion located in the middle mediastinum. The patient was asymptomatic and no significant findings were found on physical examination. Resection of the mediastinal cyst was performed by video-assisted thoracoscopic surgery. The complete absence of the pericardium was immediately observed along with a cystic tumor arising from the mediastinum. After the resection of the cyst, no additional procedure to reconstruct the absence of the left pericardium was performed. Pathological diagnosis was a bronchogenic cyst. Congenital absence of the pericardium may be associated with the bronchogenic cyst and complete absence of the pericardium requires no additional surgical reconstruction, if remaining space in the pleural cavity is small enough to avoid cardiac disposition after surgical resection of the cyst.

Selective removal of carbon dioxide contained in the effluent from ion chromatography suppressors using a new non-vacuum device.

In this paper, a new CO2 gas removal device optimized to selectively remove CO2 gas contained in the effluent from suppressors used in ion chromatography (IC) under non-vacuum conditions is described. This device consists of a closed vessel equipped with gas permeable tubing (GPT) and a CO2 adsorbent. During operation, the CO2 adsorbent adsorbs CO2 gas in the vessel, creating CO2 partial pressure difference between the inside of the GPT and the vessel. The CO2 gas contained in the effluent being pumped into the GPT is selectively removed from the effluent based on the diffusion of the CO2 associated with the CO2 partial pressure difference. The purpose of this study is to optimize the IC operating conditions with the aim of selectively removing HCO3(-) (CO3(2-)) contained in the effluent and reducing the electrical conductivity of the effluent under non-vacuum conditions. The electrical conductivity of the effluent and the signal intensity of the water dip is decreased by approximately 25 µS/cm (from 30 to 5 µS/cm) and by approximately twentieth, respectively, using the optimized CO2 remover. In addition, the anion detection limit achieved in IC instruments with a CO2 remover is on the order of a few ppb.

Fluorescent character of Cu(I/II) complexes with bisquinoline-based ligands and fluorometric detection of reductants.

The fluorescence ligands N,N'-bis(2-methylquinolyl)dimethylethylenediamine (BQDMEN) and N,N'-bis(2-methylquinolyl)dimethyl-1,3-propanediamine (BQDMPN) were synthesized. [Cu(II)(bqdmen)](2+) and [Cu(II)(bqdmpn)](2+) were prepared, and their reduction to [Cu(I)(bqdmen)](+) and [Cu(I)(bqdmpn)](+) was confirmed by the observed UV-Vis spectral change. Then, the fluorescence of [Cu(I/II)(bqdmen)](+/2+) and [Cu(I/II)(bqdmpn)](+/2+) in aqueous solution was characterized; [Cu(I)(bqdmen)](+) and [Cu(I)(bqdmpn)](+) were found to fluoresce in aqueous solution, whereas the fluorescence of [Cu(II)(bqdmen)](2+) and [Cu(II)(bqdmpn)](2+) was completely quenched. On the basis of these findings, fluorometric detection of reductants with a flow-injection system using a [Cu(II)(bqdmen)](2+) or [Cu(II)(bqdmpn)](2+) solution as a carrier was explored.

Development of a new suppressor for the ion chromatography of inorganic cations.

This paper reports on a new suppressor that can be used in the ion chromatography (IC) of inorganic cations. The space in which the electrode is set on both sides of the device is separated into three cells using anion- and cation-exchange membranes. Each of the cells is packed with either an anion- or cation-exchange resin. Anions in the eluent and injected sample are removed by electrical regeneration, based on the electrokinetic phenomenon on both the surface of the ion-exchange resins and the membranes. The electrical conductivity of the suppressed eluent reaches a level similar to that of ultrapure water; therefore, a cation detection limit of sub-ppb order is achieved in IC using the device as a suppressor.

Rapid determination of isoamyl nitrite in pharmaceutical preparations by flow injection analysis with on-line UV irradiation and luminol chemiluminescence detection.

Isoamyl nitrite is used as a therapeutic reagent for cardiac angina and as an antidote for cyanide poisoning, but it is abused because of its euphoric properties. Therefore, a method to determine isoamyl nitrite is required in many fields, including pharmaceutical and forensic studies. In this study, a simple, rapid and sensitive method for the determination of isoamyl nitrite was developed using a flow injection analysis system equipped with a chemiluminescence detector and on-line photoreactor. This method is based on on-line ultraviolet irradiation of isoamyl nitrite and subsequent luminol chemiluminescence detection without the addition of an oxidant. A linear standard curve was obtained up to 1.0 µM of isoamyl nitrite with a detection limit (blank + 3SD) of 0.03 µM. The method was successfully applied to determine isoamyl nitrite content in pharmaceutical preparations.

Chemiluminescence detection of glucose using Ce(IV) oxidation in a batch system.

A chemiluminescence method for the determination of glucose (GC) using a batch system made in our laboratory is proposed. The method is based on measures of the chemiluminesence intensity from a batch of sample GC solutions following the injection of an (NH(4))(2)[Ce(NO(3))(6)]-[Ru(bpy)(3)]Cl(2) solution. The effect of the Ru complex concentration on chemiluminescence was studied. The detection limit was 0.5 × 10(-8) M, and the linear calibration curve reached 10(-7) M. The Ru complex was selected on the basis of its desirable performance compared to those of other photosensitizers. However, flow-injection analysis (FIA) using the Ce-Ru complex reagent was not applicable for the detection of GC.

Development of an anti-analyte ion remover used for ion chromatography: Part 1. Examination of a device for anion analysis.

Herein, we report on the fabrication of a device for removing cations of an anti-analyte ion contained in a sample and an eluent under an electric field. The space in which the electrode is set on both sides of the device is separated into three cells using anion and cation exchange membranes. Each of the cells is packed with either an anion or cation exchange resin. Cation removal is performed by electrical regeneration, based on the electrokinetic phenomenon on both the surface of the ion exchange resins and the membranes. It was verified that the developed device has a very low dead volume, and sufficient capacity for the continuous removal of cations from the sample and the eluent. In addition, the detection sensitivity of ion chromatography (IC) was improved using this device as a suppressor, and a detection limit of anions on the sub-ppb order was achieved.

Rapid method for simultaneous determination of nitrite and nitrate in water samples using short-column ion-pair chromatographic separation, photochemical reaction, and chemiluminescence detection.

A rapid method has been developed for the simultaneous determination of nitrite and nitrate. The separation of nitrite and nitrate was achieved using an octadecylsilane (ODS) short column (5 µm, 20 × 4.6 mm) with 10 mM of borate buffer-methanol (99.5:0.5, v/v; pH 10.0), containing 5 mM of lauryltrimethylammonium chloride and 50 mM of NaBr. These ions were detected by luminol chemiluminescence following online UV irradiation. The calibration curves of nitrite and nitrate were linear in the range of 1.0 × 10(-7) to 2.0 × 10(-5) M and 1.0 × 10(-6) to 2.0 × 10(-4) M, respectively. The detection limits for nitrite and nitrate were 0.05 and 0.4 µM, respectively (with a signal-to-noise ratio of 3). The precisions of peak heights for 7 identical injections of a standard mixture of 0.50 µM of nitrite and 5.0 µM of nitrate were 2.7 and 2.1%, respectively. Analysis time per sample was less than 2 min, and system pressure was low (2.1 MPa). The proposed method was successfully applied to water samples from various sources.